Am I wrong for not being happy about my mom’s new relationship?

So my (30 F) mother (62 F) has a new boyfriend. Which would be fine, but my dad just died in April of this year. They were married for over 30 years and less than 3 months later she meets a man (let’s call him Gary-67 M) who is still married. Apparently he’s been “estranged” from his wife for an extended period of time.. but I’m not feeling it. I have 3 children of my own and it was a big blow to my family when my father died because my husband’s dad lives out of state, they’re not close. And we went no contact with his mother years ago due to a bunch of betrayals, favoritism to certain grandchildren over others, etc. Now it feels as if my mother died as well because she’s no longer acting like herself. Yet when I bring this up, she claims that “Gary is making her want to be a better version of herself and is the best guy she’s ever met.”

So now she’s been with him for a period of less than 6 months, he says he’s talking to a lawyer and is going to get divorced and “settle things” after the new year. She’s planning on marrying him and changing her last name. Mind you, she never changed her last name for my father. I’m just having a hard time and feel so alone. I know that I should try and be happy for her because her and my dad didn’t exactly have the best relationship, but I can’t help but get angry because she stayed with him throughout everything and cried daily up until the day she met Gary. After that, it’s like nothing has existed but him. And for a while there, she was crashing out over things like him not being able to come over for their weekly dinner at her house until I point blank told her she was acting ridiculous and like a teenager. Not to mention she will try and tell me about their sex life. I just need my mom sometimes, and I feel like I don’t have that at all anymore. We can’t even have a conversation without her bringing him up or trying to read me text messages of hers and his. She’s also completely changed her eating habits to what he likes to eat since he “doesn’t eat salt or sugar in his food” and avoids carbs. And she doesn’t cook anymore unless he comes over to her house either. Like if my kids do get the opportunity to go over to her house and spend time, I will have to plan on feeding them even if they come back over to mine at 7:30-8 pm. And I’ve talked to her about this before, trust me. She always has some excuse about her changes saying “I don’t want to live how I lived before.” There was also an incident where she agreed to watch my kids for a few minutes while I put my groceries up. Before even 15 minutes went by she called me asking when I was coming to get my toddler because “she is too hard to watch by the pool.” I went to get her, but turns out she was trying to tan her legs instead of watching the kids like she agreed to do for about 30 minutes so I could get everything put up.

To add to this, she also owns her own business and it was a known thing within our family that she’d never take off work or change her schedule. Even when my 2nd and 3rd children were born, she didn’t shut her business down to come see them. She waited till her shift ended or the next day if she was off to come to the hospital. She missed my SIL’s graduation as well. Yet, now that she’s met Gary, she will take off a whole day of work to go on their weekly date. Yet when I have asked her if she could watch my children (I offered to pay her btw) twice a month so that I could go back to work PRN, she declined and said that since her and Gary go out of town “she didn’t know if she could commit to that many days a month.” And honestly, I wouldn’t have asked her if I had other options. But every single daycare in my area is full and I’m on the waiting list.

And as for him being married, he told her that he’s been estranged from his wife for over 15 years. That he hasn’t officially divorced because he didn’t want to lose a bunch of money and he needs to liquidate some of his assets (I’m not the best with these terms, but this is my understanding). I already told her I don’t understand how funding her lifestyle and paying for her home for over 15 years makes any sense. I feel the amount of money he split with her or even the amount of alimony he would’ve paid would have to even out with what he’s been paying by staying married to her, but whatever. I don’t believe the story. However, she’s met a lot of his friends and all of his sisters who corroborate this story and claim it to be true. And also claim that he, indeed, cannot stand his wife. He apparently has his own house and she has her own and he just gets her to sign his taxes every year and that’s it. I guess she has a debit or credit card of his to fund her lifestyle (since she doesn’t work).

Lastly, I realize that my mom deserves to have her own life. My problem is she has become so obsessed with this man that family is not her priority. I was assuming that she’d actually be able to spend time with us and be a real grandparent-figure once my dad passed since he was so sick and she was the main one taking care of him (which took most of her time aside from work, understandably). I figured she’d find some new hobbies, friends, and spend more time with family. And maybe eventually start dating casually, maybe. But she was adamant that she’d never remarry after my dad died, making me even more angry for some reason now that I think about it.

Now she’s either “too tired” to do things or has plans with Gary. And usually, she’s too tired because he comes over to her house late and stays till AM hours then goes back to his house prior to work apparently. The biggest part that irks me so bad is the fact that I will mention something like going to see Christmas lights with my kids and she will say “won’t it just be so much easier when Gary settles ‘his situation’ and we can all do things together?” I am honestly offended by this and told her that. I don’t feel like she should be too busy or too tired to come to events with my kids and I, but suddenly want to come to everything if Gary is able to come. Not to mention her trying to call him “paw paw Gary” to my children. She’s also mentioned the kids coming over to see her and “paw paw Gary” when they eventually get married, which is insane since she barely sees them now. I don’t understand why she would suddenly want them around more often once he’s there.

On one hand, I have thought about seriously limiting contact. On the other, she is the only family I have left and I already feel like a failure for not having these connections for my children. We also are next door neighbors and my husband and I are not in the financial situation to be able to move unfortunately.

But am I wrong for not being happy for her? I honestly resent this relationship and wish it would end. However, I don’t think I’ll ever be able to see my mother the same way that I did before this happened. It gives me the ick and I honestly don’t want to meet him until he is divorced (if that ever happens, that is). If anyone has any questions, feel free to ask. I’m sure I’m leaving out some details, but I tried to include most of the important things without making this too long and drawn out.