My Dad hit me and im not sure what to do?

There isn't any excuse for what your father did, and if you are concerned about your little brothers, you need to at least contact social services. What makes you think he won't go after them, or hasn't been? Everyone is always sorry afterwards, but nothing justifies getting hit, you could have been as angry as you can be and swearing your head off, but that does not justify physical violence, legally or morally. You should have called the police. At least see a domestic abuse counselor, someone you can talk to about it for free, and privately. Your county and state have services available. But don't just ignore this or "suck it up," that's nonsense, and don't buy that, I'm sorry, it'll never happen again, because he needs help as much as you do. Good luck.