What to do with my dad? What is happening?

Depending where you live, you might have a choice contrary to what he said. Where I live, in Canada, the children can have a say when they re over 14. I dont know about the procedure in the USA, but here, the child would be heard in family court and the judge would decide about a revision to visitation rights if there are grounds. Verbal abuse hurts also even if he never hit you. His anger seems to be too irrational and you are justified to feel threatened by it. He may have some serious psychological problem presently if he explodes for no reason at all as you described and it is a new thing in his behaviour. Who knows, he may even have a brain tumor if his behaviour changed suddenly in the way you described.