My 19 month old Son's behavior is terrible

For about a month now my son has been a little terror. To start he is always throwing fits and hitting and kicking me when he knows he is in trouble. I put him in his crib when he gets a time out. And when I put him in there, he throws himself backwards and hits his head every time on the bars of his crib. He can walk okay but still trips all the time and I have to watch him around the furniture so he doesn't hit it. I just want to know if this is normal like the terrible twos or if there might be something wrong with him. Please help.