What is it?

Your dad must be blind. And if he really likes her, then talking to him might make him tell her and she'll only act worse to you. I feel really sorry for you. I'd suggest moving out as soon as you're old enough. You can be eligible for a youth allowance as it doesn't seem to be suitable for you to live at home. You need to talk to a school councillor/social worker and let them know what's going on at home. In the mean time, would it be possible for you to stay at your friends' houses or something as often as possible?