I wish you all the best and all the luck in the world. Unfortunately(in this case) the father of the baby will have the right to be a major part in his child's life and can make your life very difficult for many years to come. By deciding to have this baby you are forever linked with this guy, and from the bad things you have mentioned about him around your other kid, I wouldn't want any child of mine anywhere near him, but you won't have a choice. He can even end up with at least joint custody if he wants and you can't do anything about it. I'm just sad to see a child being born to a father who is, at least verbally(so far, who knows what more abuse he's capabel of when he'll be alone with a child, bad words could be just the beginning!!!!) so abusive.
Good luck to you.