It's important to try to replace that injurious behavior with something else. Preferably something positive. Even if you have to throw something soft or scream it is a better alternative.

Do you usually know when you are getting angry? It may help to identify your symptoms that lead up to the anger -- so you can already be thinking about that alternative positive method when you go for the impulsive reaction.

Our heads are built to take punishment but if you keep giving yourself concussions you could end up with some serious brain damage. Especially if one day you hit at a softer angle. I'm sure you have been told this before.