I badly need some direction or advice!!!!!! I don't know what to do :( Help?

Okay, so I was friends with this boy for about 3 years and we became pretty close to where I considered him to be one of my best guy friends. We were each others date to our senior prom and the night of prom we both were drunk and ended up hooking up and having sex that night. I wouldn't say I regretted it, but earlier in the night he confessed his love for me while we were drunk and that's all of what I remember. But I feel that just complicates things because I don't really feel that way towards him. I know it may sound screwed up to have drunken sex and then exclaim how I don't feel that way towards him and I also realize that saying "I was so drunk" is no excuse..but everything just sounds like a good idea when your drunk..if anyone can relate with this? :/ Well that morning wasn't good and we got into a pretty big argument. Since then, he's threatened his life numerous times saying how literally has no one else, no friends, his family treats him like **** and feels that I'm the only thing keeping him alive. One night we got into another huge argument and I told him I couldn't help that I don't feel the way he does towards me. Then after a lot of thought, I feel I was being ignorant for not just trying it out. So i decided to date him and see how things go. Well, almost a month into it, and I've noticed that literally all we do is fight and..have sex. It's getting to a point where I just cannot handle it anymore and I just don't want to be with him. But every time I try to get to saying that, he freaks out on me and threatens his life and then I have to talk him out of it again saying it'll work. I don't know what to do at this point because now I just feel stuck and my stupidity got me in this situation. I feel like I pretty much hold his life in my hands and that's a horrible feeling. I feel like if I break it off, then he's going to probably kill himself. and every time he says he's going to do it..it just pushes me even more away from him. I don't want to be with him..but at this point I feel that if I'm not he's going to do something bad and it'll be my fault. Any advice whatsoever? I already know I'm an idiot for sleeping with him in the first place so please don't just criticize me solely on that.