I kinda read the other responses, but a little tired, so sorry if this has already been mentioned.

How about taking up an agressive (but controlled aggression) sport. Like kick boxing, Judo or something along those lines. Your anger should be let out, and if it has to be physical, then something like that might help.

I wanted to also say I know how you feel, I have noticed a definate shift of my personality within the past couple of weeks. My anger has gone right up, when before I did get angry, but not at everyone and everything regardless of if they've actually done anything wrong. But I cannot express my anger physically, other than s/h behaviour, as I am too scared of that.