My son bangs his head on the floor when he's angry?

Okay, my 21 month old son is very temperamental, he likes to get his way. He very hyper, and into everything. When he doesn't get his way he is starting to get worse. He will seriously bang his head on the floor, on purpose. How should I deal with this? Yesterday, I actually held his forehead to soften the blow when he hit down, and picked him up to restrain him from hurting himself. I would like to just ignore him, but don't feel like this is an option anymore. When I brought him in from the car yesterday, he was screaming because he wanted to "drive" the car and I put him in the high chair and he was banging his head on the back of the high chair. Some blood started running out of his nose! I think it was from working himself up crying so bad, but it scared me. Has anyone got any ideas? Thanks!