In a relationship with an Alcoholic, 11 weeks pregnant!

Me and my boyfriend have been dating for about 8months. When we first got together it had been almost two years since I've seen or talked with him. We meet back in 2010 and would reconnect throughout the years. Well he explained to me when we first started talking that he just got out of rehab for alcohol abuse. I won't lie it scared me but I wanted to give the man a fair chance. Now I know that was the biggest mistake ever ! I ended loosing my apartment I had with my 2year old son due to Financial problems and he decided it would probably be good if I move to New York to get a fresh start because I have recently just lost my sons father due to robbery. When I moved here everything was going great until a month ago, he started drinking again. At first it wasn't so bad but I knew it wasn't right. Well last week we were having a great day putting up the Christmas tree and cleaning the house and he started drinking at some point. When I noticed and I got upset and he knew it but that mad him angry and attacked me. He got in my face like he wanted to hit me, being 11 weeks pregnant I got scared and didn't want any harm to my baby. So I pushed him away and told him to please claim down and leave me alone. That made him more upset and he pushed me even harder until he knocked me down on the floor. I hit my head. I started crying and he got in my face and called me a Stupid bitch. He then spit in my face . I looked at him because I couldn't believe this was happening and I wanted him to see how bad he really hurt me but I realized that he wasn't himself and it felt like I was face to face with a demon. The next day he sobered up but he didn't remember anything from the night before. I kept telling him I was leaving and going back to my hometown. He apologized of course but it didn't mean anything to me because I know with him having this addiction it will be hard and he will do it again, but next time I might not make it it alive. He threated me while sober and said that if I left him he would do what he had to do as far as moving on. To be honest that didn't bother me one bit. And what sucks the most, I am pregnant with this mans baby. I am so stressed I don't know what to do