I'm 36 weeks pregnant and i'm in an abusive relationship, help?

Here's my situation, to start off with i'm not being physically abused, but emotionally, to me it's still terrible. My boyfriend and I tried to have a baby, and we succeeded, we were both so happy. He has always wanted a son and he has got two jobs and he's trying to provide for me and our unborn son. The problem is, when I found out I was about to leave him for cheating on me and for being, what I think, is an alcoholic. He hadn't been cheating long but either way he was. When I found out I was pregnant I was excited but scared because we moved to the same city together to go to college and I do not know anyone else here, so I felt that I couldn't leave. He was so nice to me at first, cooking for me, and doing anything he could for me, but on his days off he would get wasted! He said he was under so much stress over being a good parent and he needed a break from working so much. Soon after he quit having sex with me, he quit holding my hand or showing me ANY affection. We still went out on dates but he treated me more like a friend. I started to catch him on porn sites, and online sex chatrooms, and I flipped out on him because i'm 5months pregnant & I ask him all the time to have sex with me but he won't. When I confronted him with the rumors at our college of him cheating, the porn, the sex chats, the alcohol he freaked out on me cussed me out started throwing things and said that I was a bitch and all these nasty names and said I don't appreciate him working to provide for us and all I do is nag him and for me to never speak to him again. So I started looking for apartments of my own and changed my computer password to keep him from chatting on sex websites he called me a cheating whore! The next morning however, he cooked breakfast for me and kissed me on the forehead before he went to work, but he never apologized. Just tonight we were suppose to go to his friends for new years because he asked me to go and I agreed, so I go to take a bath and he is taking a nap on the couch when his phone started vibrating. Knowing he emotionally cheats on me with other girls by flirting, I took his phone and saw where some girl told him goodnight but i dont know the story so I didn't get mad at that, what I did get mad about was he told the same friend we were going to the new years eve party with that he doesnt "like me right now" and that I was being "a bitch about him getting wasted tonight". However I never had a conversation at all with him about him drinking tonight, he completely made that up. I need help because I think he's crazy, I only confronted him two times about things he was doing but he says he isn't doing anything at all wrong and all I do is bitch all day long, when I make a point NOT TO. Also he works and all his pay checks he wastes on lottery tickets and beer. I've had to pay the last two months rent with money my dad gives me every week to help me out! I grew up without one of my parents and I don't want to put my son through that but I know I have to. Can someone tell me why they think he is acting so weird? why he is so nice for a few days and then he goes nuts the next..He tells his mom we are going to get married and acts to her like nothings wrong. Also how do I go about making him move out of our apartment when I know that neither one of us has anywhere else to go?