self sabotage?

Hi all,

I’m talking to this guy for 3 months and everything has been going really good we have had little arguments here and there but we kind of just jumped into to things literally the first night explained his flaws to me and I explained mine so no real “cupcake stage” as of late everything has been AMAZING he came over to my house and we had sex nonstop drunk and laughed all night and it was just perfect so the next morning I asked to see his phone because he recorded a few videos of us and I wanted to see how they looked (I’m a little insecure about my body so he knew I’d be upset if I couldn’t see them) I was watching the videos and a notification popped up from Instagram I clicked it and it was messages from lots of girls but one in particular sent him a nude and his reply was “perfect ass body” she was skinnier than me and I gave him his phone back and he immediately knew so we got into a huge argument and he basically said he has a problem with commitment and has a bad habit of self sabotaging when things are going well because he doesn’t think he deserve to be happy and growing up all of the men in his life brainwashed him to believe this is how he should be I’m so confused and I know it’s only been three months but he literally treats me exactly like a girlfriend without the title and I just need help any advice?