What should I do?

For almost over a year my boyfriend and I have been having trust issues. It started when my ex decided to interfere with our relationship. He wanted to catch up and so we went to a local Starbucks after he kissed me and I told my boyfriend. I believe he thinks more happened and he’s upset because the day we hung out he was at home sick. I went to see him right after and told him everything. That was back in December of last year. In Jan I saw he was snap chatting this girl and he said it was because he “just wanted someone to talk to.” We got into an argument and we agreed to let it go and for him to remove her from all social media. When he did everything was good. In the summer I found out he had lied because the girl he was snap chatting was “a girl he was trying to hook up his friend with” so once again I got mad but he brought up my ex situation. We have been rocky but working through everything. I recently got his Instagram information and saw he was messaging a girl from his college, who has a boyfriend but they were planning on meeting up. I comforted him and said he only wanted to make a friend since he commutes to college from home. I understood that but I still wasn’t pleased he did it behind my back. It wasn’t the first time he has done something like this and I even asked him when this whole fighting fire with fire would stop. Since than I made him share his location with me because he has a record of lying. He stopped sharing his location because he said I abused it and that he wanted me to trust him without having to check where he was. Whenever he went out he wouldn’t text me and said “if you wanted to know where I was you have my location” and we would argue that it’s not fair for me to relay on the location when it wouldn’t kill him to shoot a text. I have tried to sit him down and talk to him but he will either get annoyed or get mad. Since on his account he hasn’t done anything wrong. He changed his password only a few days ago which logged me out of the account and denied that he did. I was able to get back on and saw he unblock the girl and requested to follow her again. So I talked to him and he went off about how he did it to “test” if I was still on his account and would have blocked her again if he saw I stayed off. He is now mad that I won’t tell him how I got onto his account but from my perspective I have caught him messaging girls on either Instagram or Snapchat and I have even told him that has made me more spacious. Somehow he has turned everything onto me and making me the bad guy. Whenever I get mad I always end up feeling like the bad guy since he finds a way to twist the problem to me. I don’t want to break up with him because I feel like we can work this out it’s just a matter of talking but I don’t know how to get through to him. I’m away at college and I’m trying to trust him but that whole situation happened only a month into school.