Well first off I am sorry about your break up. A few things you can do to help your self is when you feel these urges of violence and depression just find someplace quiet and just take a minute to relax and think. taking deep breaths also helps. When your upset try talking with someone like a teacher of a trusted friend. As for your relationship try talking calmly to her father. But make sure that the girl is in the room or in earshot and she knows about this meeting. If things don't work out give it some time and try again. But other times its best to just accept whats meant to be is meant to be.

If you beat someone's head against the locker i doubt it would soothe your pain, it will instead cause pain to the kid, and since you felt alot of pain why would you want that to happen to the kid, that violence isn't going to solve anything but cause more pain, also try getting medicines for the mood swings it might help u talk to the dad in a more rational mindset.
Ps there are a lot of chicks in the world , or wait till she moves out of the house when she turns 18 or so?