Mess mess mess

Boyfriend went to a party and cheated on me with this girl. He told me he didn’t do anything with her and just talked. So I believed him because I didn’t go to the party and I had no evidence that he cheated. However, I saw on Instagram that he added her but I believed maybe just as friends since they “talked” at the party. However, a day after this party he broke up with me, it’s been only 10 days and now I saw that he posted her and he’s already seeing her. So it’s more than obvious that something did happen at this party, since he broke up with me a day after the party and now he’s seeing her. It’s been only 10 fucking days from him breaking up with me. The day he broke up with me he was giving me excuses as to why he’s leaving and never told me that he cheated. I’m so angry at myself. He’s done this many times before where he’s met a girl and then leaves me for them like I’m shit. We have been 5 years together and it’s crazy. I’ve given him so many chances before thinking that he loved me and that he would change but it happened again. I’m in shock. I should have never taken him back all those times. This is the same girl that one of his best friends has dated when he was 15. This girl ended up cheating on his best friend with other guys and then after they broke up, my now ex boyfriend was trying to flirt with her and date her. He would tell me how much of a hoe she was for having done that to his bestfriend and now look he’s already seeing her. What a mess, I’m so disgusted.