You sound very depresssed hun, and when someone's like that, it's very difficult to find inner strength to help yourself. Try and sleep if you can - I know it's not easy at all, but you can come through all this if you get away from the person who's with you at the moment.
When you do, don't ever be tempted back if he turns "nice" again. There are some wonderful guys out there, so think well of yourself, and you'll attract the same type. When it's light, gather your thoughts as well as you can, and do some of the things that've been suggested here. There's an answer to everything, but it's just finding it, so do something positive and see if any of these things work.