Fwb is Alcholic

I just came to realize that my FWB (friend with benefit) is an alcoholic and becomes violent when he drinks. Well I went to his house to hookup. As usual. Usually when I come over, we drink. This time when we were drinking, he threatened to hit me because he was paranoid and suspected that I wanted to hurt him. Mind you, I had no intentions of hurting him in any way. I didn't even touch him, only when I had to defend myself. But when I told him I wasn’t going to hurt him (I never had), he slapped me across the face. My initial reaction was pure shock; this is the first time he has put his hands on me. I felt like I did nothing to deserve him putting his hands on me, and when I tried to leave after that, he begged me to stay. Mind you, he was drunk. I didn’t know how drunk he was, but he definitely was not fully aware of what he had just done. I ended up not leaving, and the entire night he got more and more violent. He choked me, threatened to stab me, etc., and his true colors were shown. That same night he had gotten into a fist fight with his dad, and I was there to witness it. I opened the door to see him getting pushed through the hallway by his father. Little does his dad know he’s a drinker who drinks all day. Possibly to cope with something I’m not sure. He’s been through a lot. His dad threatened to kill him, and all that happened before my eyes. I was in pure shock. His dad ended up kicking me and him out of the house, referring to me as a bitch. “Get you and that bitch out of my house.” I couldn’t believe what was happening. But like an idiot, I allowed him to come over to my house and stay the night because he had no where else to stay for the night. It’s so sad. I thought all of this was. Crazy experience. And it’s sad, but I should’ve defended myself. I don’t know why I allowed all of this to take place.

I vowed I’d never let another guy put his hand on me and it did. He’s clearly alcoholic and he’s the only person who doesn’t see that. I want to help him but I can’t he has to help himself because he doesn’t think he has a drinking problem.