My best friend has cut me off due to other friend telling her false info and I don’t know what to do?

Hi so to give you some background. I have a best friend (I will call her Mia to keep it private) that I’ve been friends with for nearly 16 years. I was her maid of honour at her wedding, we have matching tattoos, we’ve been through everything together and it’s been amazing. We message each other daily and some days even call each other and be on the phone for over 2 hours just talking about life and inside jokes etc.

Well the other night I got a very random message from her saying “I’m giving you the chance to be honest with me here” and I was so confused and wasn’t sure if it was meant for me or not because the last things we had discussed was about her coming round to my apartment for a weekend (we live in different cities, so don’t get to see her as much in person) so I replied with “what? Xxx” and she then went on a massive rant about how I’m a liar and all I do is lie to her and manipulate her? I was so confused because first of all I don’t lie and second of all I don’t manipulate her in any way? So I was confused if it was supposed to be for me so I tried phoning her, but she didn’t answer and I got another messaged saying “Hello this is her friend Grace and I think you are disgusting with what you do to Mia. You always act like a victim and manipulate her to get sympathy and it makes me sick. You need to leave her alone now because she doesn’t want to talk to you anymore” Now I’ve met her friend Grace a few times, never really liked her though as she always came off as one of those bitchy toxic girls who love themselves too much and thinks they are everything. This made me so confused though because I didn’t know where any of this was coming from because a few hours before this I was telling Mia about how I’ve booked us in to do karaoke and bowling for when she comes round for the weekend, so I was very lost and also annoyed that instead of just answering my question herself. she got her friend Grace to message me from her phone.

I tried phoning again, but they just kept on sending me to voicemail. So I sent another message telling them that I’m very confused and can they explain why they are saying all of this and instead of answering that, her friend Grace messaged me again saying “You make me sick! I don’t know why your boyfriend puts up with you because if I was with you I would be running away as you are nasty and mentally disturbing I’ve told Mia to not talk to you anymore as well because you’ve made her cry” So I was getting rather frustrated because I didn’t understand what they were on about and how I had made Mia cry? So I replied “Grace what is going on? Why is Mia crying? Can you please just answer the phone so I can talk to MIA not you because I’m lost on what’s going on” and then it got worse…

So another little backstory back in January I unfortunately suffered a miscarriage at 12 weeks which really messed me up mentally and lead me to self harm and gave me very severe depression and Mia knew all of this and obviously must of told Grace because Grace then sent me a message, still from Mia’s phone, saying “you put all your issues onto Mia and it’s not fair on her you are trying to get sympathy from your stupid miscarriage that I believe was a big lie as well! I bet you weren’t even pregnant and you are just using it as an excuse to get attention and sympathy from Mia. You need professional help so from now on you leave Mia alone” This message made me feel sick! To bring my miscarriage into whatever this is, which is something that has a lasting effect on my life. Also I was pregnant because I remember when I found out I had sent a picture of my pregnancy test to Mia, so how was that a lie? Also I would NEVER lie about that because that’s a disgusting thing to do. I got very upset at this point and very angry and told Grace to leave me alone and to stop harassing me because I have no idea what is going on right now or why I’m being attacked by them randomly. They sent one more message that just said “You need to stop lying to Mia and get out of Mia’s life because you are just bringing bad energy into it” I didn’t reply as it was past midnight at this point and I needed to try and get some sleep.

The next morning I felt really rough and still confused about last night, so I went to message Mia, because I was hoping she was away from her friend Grace now, but just as I was typing out my message I got one from her that read “I don’t understand why you were being so mean to Grace last night. Honestly she has opened my eyes to so much now and I don’t want to be friends with you anymore. Have a nice life” and then she blocked me off everything! On all social media and my number, so I asked my boyfriend if I could borrow his phone to quickly drop her a message, but she had blocked him on everything as well.

Now I’m just so confused and lost because I don’t understand what happened? Mia is my best friend and has been for so many years and we’ve been through everything together, I’ve helped her when she was going through tough times and she’s helped me. I don’t know if this Grace was jealous of our friendship and has made up something that has now made Mia hate me for some reason? But if she did, why would Mia believe her? I’m so lost and confused and I’ve had a headache all day and have cried a few times as well. I just don’t know what to do now? I don’t have many friends and now I’ve lost my best friend over something that I have no idea about. What should I do?