You are NOT overreacting. Not at all. In fact, just about the time you find yourself stepping in to protect your girls from this abuser, your next step should be to start packing. There is nothing, including any man that is worth taking the chance that your kids will be hurt. Re-read your post, and list all the abusive things he has done. You can't even talk to him. He is not interested in making any changes. Soon, his son will be abusing you and your girls as well. The greatest influence in a young person's life is the same sex parent. He is learning now how to handle himself, as he grows older and stronger, you may be sorry you did not take protective steps now.
Your girls are learning also that this is how men treat women. Don't let this go on any longer. It is not worth the welfare of your children.