Baby Daddy drama.. I really need help...?

This is tearing me apart, so I wanted some advice. I began a relationship with my ex last year in June. Around that time we had a guy move in to my house because he needed a place to stay. My dad ended up in an accident and I had to go away a while. My bf pushed for me to come home and he came to get me a few states away. My bf decided to stay the night the next week in a row.. I guess because of the other guy in the house... then he began checking my phone... and Facebook. I asked for a break so I could think... he pretended to be with four women to hurt me. Eventually things calmed down and we got back together. New Years I got pregnant. We found out Valentines Day. I was told I was infertile.. so my baby is a blessing. After he found out, he started to get controlling and possessive. He got me in his truck and drove like a madman because I didn't want to stay the night. He yelled at me till I almost passed out. Second time he told me that he's the man and I will obey him. The next night he said he didn't want to pay child support unless he wanted to. He said hed rather sign off rights to the child than pay. I asked for a break again. He never left me alone so I got mean. He begged and said he would change... again... but would turn and yell again. Say I'm a horrible mother. Next week, he rebounded. He's not asked about his son once. I'm five months along. Last time we spoke, I said is die for my baby and would have him even if he's imperfect. He'd rather have an abortion if something wrong. He told me I make him sick and he will get custody. Advice?