It's clearly a very difficult situation, but you say it was because of you. Your father wasn't put in jail because of you, or your girlfriend, or anyone else but himself, and his own actions. He should have never raised his hand to you in anger like that. You shouldn't have to deal with parents like this. If you think you could, try to get your mother to see a counsellor to deal with her anger and stress, even if you say it's for yourself but would like her to come along. Most of all, don't blame yourself. You shouldn't have to put up with this.