Feeling guilty

My ex and I dated for a year and two months. I’m a 21 year old female and he’s a 23 year old male. 3 months in he calls me his exs name whom he dated for 2.5 years. He apologized and I stayed, then a few days later I find women lotion and perfume in his room he proceeds to tell me they are his then I tell him I have the same ones it’s for women don’t lie please be honest. He says yes sorry they’re my ex I forgot to throw them away. This caused so much doubt in our relationship it messed everything up I felt that he was never over her. Then he gets invited to a wedding and he’s a groomsmen. He says he’s going on a guys trip with the grooms men and fails to tell me that the bridesmaids are staying in the same Airbnb. I felt so worried lost and insecure because that sounds really bad like he’s doing something sneaky. I argue with him through messages mind you we are still dating come to find out he tells me recently that we weren’t together during that time bc I wasn’t answering his messages. Events like this continued throughout the year I became verbally abusive towards him. I threatened to cheat on him because I was so over it. I didn’t mean it but eventually June 28 I had the chance and I cheated on him with a girl. Part of me felt like he deserved it and part of me regretted it. I told him that same morning and that’s where everything fell apart. He said he wasn’t sure if we could fix things and then he eventually reached out to his ex the one I was always worried about in the middle of us trying to fix things. I can’t help to think that I deserve it but I also think it’s very unfair after everything he put me through.