M.L.
I have a 7 year old boy, who went through the same thing. He would throw what ever was nearest to him and hit and kick at me. We started taking anything and everything away from him that he would throw, even if it was his stuffed animal that he slept with at night. He even would knock over his TV and DVD player. We kept taking them away and would do so for longer periods of time. We would also give him time out and let him sit and cry, he has bunk beds so we would make him go on the top bunk or stand in the corner. About a year and half ago he knocked over his TV and actually broke it, he still hasn't gotten a new one. He has pretty much grown out of the throwing stage and has completely grown out of the hitting stage. Only once in a blue moon will he be so mad that he actually throws things at his door any more. He also used to slam him door so for a while he didn't have a bedroom door. His latest thing was to lock his bedroom door so now he doesn't have a door knob on his door.
I know how frustrating this can be, hang in there and it will get better.