After sex depression

Ok so I'm a 20 m gay man who is partially out to a few friends (where I'm from some people still think it's wrong). The problem I have is after every single time I've ever had sex, I've always felt depressed and disgusted by the guy I'm with. Most of the time I'm drunk when I have sex but there has been numerous times when I haven't been drunk. I don't feel as bad/depressed/disgusted when I am drunk for some reason. After I come I immediately feel like I need to leave and am ashamed of what I've just done. I have always felt this way even when I first started masturbating. I don't feel guilty much after masturbating anymore though. Also when I first started having sex I was more repulsed than I am now (describing myself as ashamed). It's like I am bipolar and my thoughts completely change from before. I have never been in a relationship because of this and I worry I never will be. Unless I am drunk (or with one of my very close friends) I feel very uneasy talking about my sexuality. I don't like when my friends bring it up. What do you think is wrong with me and how can I make myself feel better after sex?