I unfriended my best friend of 8 years, in January 2018, she was controlling and rude, and I was scared of her sometimes, but because she had manipulated me since I was 11, I didn't realise this wasn't normal friendship behaviour. However I also had a boyfriend while she was around, and it was clear they didn't like each other very much.Halloween night 2018, we went out for some drinks with a group of friends, along with my boyfriend and hers, but she was in a bad mood and left without telling up, but we also noticed her boyfriend was gone so we assumed she was fine. Later that night, she sent all of us, and especially me some awful messages, and took a huge dig at my boyfriend, ultimately giving me an ultimatum, it was her or him. I choose him and she did not like it, so I became distant. I was also currently studying at university a few hours away from my home town, and a few of my other friends wanted to come visit me (Jan 2019) and we all went out for some drinks. That night she messaged and again started saying some harsh words and at this point I was done, so I told her goodbye and blocked her. It felt like a sigh of relief, however it was only me, all my other friends still hug out with her and I hated seeing their insta and snap stories with her in them, but I tried to stay positive and remain happy with my decision, and my boyfriend was fully supportive.Then I went on a family holiday, September 2019 and left the country, while I was away, I was getting lots of messages about my boyfriend being unfaithful. When I confronted him he denied it all and told me I was acting jealous and crazy when all I asked was "what's happening?" he denied anything happened and when I got back home, we had a big falling out and broke up. (we had been together for a year and a half.)Fast forward a few months, I get told my ex friend is hanging out with my ex boyfriend, I tried so hard to shrug it off and told my friends I didn't want t hear a single thing about either of them, which they respected. However one day while I was doing my university dissertation, In august 2020, I get a notification, my ex boyfriend and ex friend started ganging up on me in an old group chat, that I had forgotten existed, by sending hurtful gifs and pictures and commenting some very awful things that were clearly directed toward me. I was a bit taken back but again tried to brush it off and pretend it didn't happen by leaving the group chat.Then stupidly the day after my 22nd birthday, I get a message from a random person asking if I would consider being her friend again because she had "Changed" and me being an idiot, I unblocked her and we agreed to be friends, however we don't really talk anymore. And I kind of had a suspicion she was friends with my ex, but I also never considered it. But today, I was on snapchat, and normally, I do try to avoid looking at her stories, but something told me to look, and I did.It was a quick 5 second video of her in a car with a male voice in the background, I recognised the voice straight away.She was with him, in his car.... I feel so hurt, and betrayed. But I also fell like its my fault, why did I let her back in my life, when I knew she was gong to hurt me again. I feel so fucking stupid, but I'm scared to click the unfriend button again, I can't deal with the drama again. And I don't want to complain to my friends because I'm sure they are sick of me always complaining. I just feel so alone and I don't know what to do, or how to cope.