AITA for backing out of being MoH for my friend of 15 years and going NC after the hen?

Okay, it’s a long one so let’s start with some context. My friend of over 15 years (let’s call her Jamie -38F) was getting married to my cousin (let’s call her Lauren - 35F). Me and Lauren were close as kids but lost touch, as you do sometimes in our teens and early 20s but reconnected in my late 20s (I’m F, now 31) and became close again. Naturally, I introduced her to my best friend of (at the time) 10 years. While Lauren was still in the closet at the time, it was clear she fancied Jamie when they met, little comments and looks…it was just obvious. After a year or 2 they started dating (for all of 2 weeks before the inevitable lesbian drama kicked in and they split up). For the next 6-8 months I was stuck in the middle. Jamie complaining about Lauren calling her a psycho, Lauren complaining about jamie calling her vicious and nasty. I was tired of telling them I didn’t want to be caught in the middle and don’t talk to me about it. I didn’t want to hear my friend getting called everything under the sun, nor did I want to hear it about my family members. This fell on deaf ears repeatedly.
Fast forward about 12-18 months and they started dating again. Less than a year of dating, jamie proposed. I expressed before the proposal that it was a bit soon but if they were happy I was happy. Each to their own and all that. I was asked to be MoH and said yes happily. I offered my services and helped them hand make invitations (they took months and sent them out very late and this was due to me pushing jamie to do them because they were leaving it too late for guests to take off work etc. we done these over drinks until early hours of the morning one night to ensure they were done. They weren’t sent out until much later still with some guests only receiving their invited a week before the wedding). I helped suggesting music, going shopping and even loaning money to jamie.
Now, as most people do, they booked and planned the wedding over a year later. This was just one of the many examples where they expected others to do things and just drop everything for them. They also had a huge falling out with my uncle and aunt for not attending their engagement party as they had conflicting plans at the time (they had multiple parties to celebrate their wedding including the wedding itself and expected full attendance from everyone or they would have arguments with them for not prioritising them). 
Where I started losing respect and getting narked about jamie’s behaviour was when she would borrow money and ask me not to tell Lauren. For small amounts I wasn’t bothered but she would borrow large amounts and ask me not to tell Lauren or my partner (Andy 30M). That is where I drew the line. I don’t have that kind of relationship and I am very honest with Andy. We have been together 7 years and I’ve never lied to him. Over the last couple of years, jamie’s lies have grown more frequent ranging from small lies like how events had happened whilst out or medical conditions she had (claimed to have autism after I was diagnosed after years of telling people she didn’t have it and was tested when young. Honestly, it was weird. Why would you WANT to have a condition that impacts multiple aspects of your life unless you just wanted attention). But her lies kept growing in frequency and depth. I am a terrible liar and hate being asked to lie for people. It really sets me off and I find it very uncomfortable. 
Now, looking back we were young and dumb but me and jamie used to take dr**s on occasion. When we first met this would be every few months, festivals, events etc. but this started increasing in volume over the years and really got bad during Covid when we both lived alone and were in each others “bubbles” -all above board regarding restrictions (minus the dr**s ofc). But we would do this every couple weeks instead.  During the year of planning, I would have to repeatedly tell jamie to calm down with dr**s as she was taking coc***e just to clean her house in the middle of the week. Multiple times a week. Every week. It was turning into a problem. She was borrowing money more and more and asking me to lie more and more. Not okay. I was getting sick of this behaviour and wanted to distance myself from it as when we spoke about volumes she was taking it was never a problem. I later found out that she was getting caught by Lauren being high and saying I gave her them when I hadn’t even been with her (I know, wtf!).

The final nail in the coffin was her hen do. Jamie discussed what she wanted and explicitly requested an international hen do. It was pricey but I figured hey, if that’s what you want. Because I had other events planned that year I couldn’t go to Lauren’s hen do as well as this was going to a cabin away with the girls and was also a little pricey. Not as expensive as jamie’s but still, I couldn’t afford it. I planned jamie’s hen with 2 other people, I got T-shirts printed which not everyone paid me for, I got party favours and games which nobody played (I tried to play them but only 1 other person wanted to and I got shut down repeatedly -total waste of money and again nobody gave me anything for this). I had to loan jamie £600 to go to the hen do (that she requested and FYI she earns TWICE my wage. I have a good wage but she still earns double what I do) she also asked me to keep this a secret from Lauren and Andy. I said no and told Andy straight away. I didn’t tell Lauren straight away but this was just because there wasn’t a natural way to bring it up as I hadn’t really seen her during this time and didn’t want to appear to be stirring the pot unnecessarily. My plan was to tell if it came up but not being a tattle tale.
So, jamie has a friend who is categorically the bitchiest gay man I’ve ever met. I have some wonderful gay friends and even they hate him because he was so bitchy and over the top. He doesn’t like me. And honestly I’m okay with it because I don’t like him. Every time we would drink together in the same event etc he would be vicious toward me (and others but they excused his behaviour as this is “just what he’s like” -F that. I’m not friends with people like that, why would you choose to keep company like this but whatever. They’ve known each other since childhood. On the hen, Lewis (38M - bitchy mcbitcherson) was overly vicious toward me. Like seriously overly vicious. (Going back a little, jamie asked a friend on then hen to arrange dr**s while we were away, I reluctantly agreed to it after she said “if you loved me you would” which she would say regularly but was unsure about sourcing this in another country. I still did some but hey, that’s on me and not the point of the story -I no longer touch this stuff and barely drink since going NC. Turns out I cave to peers pressure, I was that Idiot). Anyway, jamie overhears a conversation that I was having with one of her friends that was there that I used to work with, I asked about jamie’s ex (we worked together for a long time and prior to this friendship we were in the same social circle, I also asked about other people in the old group) but apparently this was wildly inappropriate. She was also annoyed that I corrected the dating timeframe of her and Lauren as they tend to add the year they were split up into how long they have been together. I know it shouldn’t bother me and just let them get on with it but my little tism brain just can’t help it and I correct it’s been 2 years, not 3. I found out the next day to be discussing her ex on her hen And this little correction that jamie and Lewis were pi***d about it. Someone did ask why I no longer spoke to the ex, and I did (drunkenly and I might the the AH here) explained that it was because when she blocked jamie years ago, she sent a message from my account when she was still hung up on her that was insane and inappropriate from me and I just had to roll with it and pretend it was from me. Did she ask? No. Did she care? No. It always narked me that I lost a friend through her but this was years previous and for this, I might have been the AH. I also don’t really care at this point as I had to just cover for it. 
I later argued with Lewis for being vicious to me for hours on end after half the hen party left and went back to the hotel, when we were back in the room, I mentioned it a few times to jamie and she agreed at first and again used the old “that’s just what he’s like, you need to get used to it” -I don’t. He’s not my friend. I don’t need to put up with that. Her other friend, let’s call her Anna, likes to stir the pot. After a 5 minute chat with her suddenly I had ruined her hen (the one who booked, paid and organised and tolerated sh***y behaviour from Lewis) clearly ruined the whole weekend with 2 comments she never even mentioned to me, simply overheard 2 snips of conversation, filled in the blanks herself and assumed the worst of me. This was also night 2 btw and we had already had time away and been for drinks on night 1). 
Anyway, the last day of the weekend, the whole group shunned me and left me alone for a whole day in an international country. Nobody made contact. I spent the whole day on the phone with my sister and mother crying as I was in another country alone with nobody to talk to. I booked an earlier flight home and left a day early.
When I got home, Lauren had already been arguing with my mother saying I ruined the hen and asking why I didn’t ring her. She had already heard a string of lies and would not listen to my side at all. As far as I was concerned, It wasn’t her business, she wasn’t there, she wasn’t part of the argument and honestly I thought it was going to blow over. It escalated quickly and my whole family was arguing about it. I may add, only Lauren and her mother were not in agreement with me. Turns out jamie made up a few stories telling 4 different versions of the same night - nobody had an answer when I pointed out that it was impossible for all of these incidents to have happened in 2 day as and the stories directly contradicted each other. She also said i wasn’t to be trusted as i was on dr**s. I went to bed at 1/2am and she stayed up all night continuing her party after i left post argument. After a week of this BS, I messaged Lauren and told her to make sure I got my £600 back that jamie borrowed and asked me to lie to her about. I threw her under the bus for multiple other lies as I was DONE. I messaged jamie and said I wasn’t going to be her MoH anymore. She asked if I wasn’t still going to the wedding, I said no. Neither was my partner, my mother or father. I then went NC. Around 10 other family members dropped out of being guests and I got blamed but honestly if It was my fault, they would have been on your side and attended. I didn’t want to make sides, I didn’t want my family involved at all but you reap what you sow and jamie’s lies and dr*g habits got far too much for me. Since then she has expressed to my sister how much of a shame it is that we aren’t friends any more. I laughed. I will never acknowledge her again. Good riddance. As for Lauren, she blows hot and cold and honestly I’m not bothered about that either. Like me, don’t like me. I don’t care. I have everything I need in my life and no regrets for going NC. I wish I could have been there for Lauren but I could not stand and celebrate a woman I now couldn’t stand or have any respect for. 
so, AITA for going NC and cancelling on being MoH?