Pregnancy relationship

I been dating my fiancé for 2 years going on 3 we always had a rough relationship, dealing with other females. A year ago he went to prison & I stuck around one of the hardest things I had to deal with I found out I was pregnant while in the process of miscarriage, I got so depressed not having anyone around while he was in prison. As soon as he got out I got pregnant I thought he's head was in the right space due to him being in prison but I was wrong I feel like my whole pregnancy has been a battle with him, he has a drinking problem he doesn't realize. I just feel lost I love this guy so much be in constantly stressing over everything he does to me, I really don't want my daughter growing up without a dad but I'm lost, It's like I want to leave but I just can't seem to let go