I just did the worst thing ever.
What caused you to do the worst thing ever?
I don't like the guy, he was an ignorant prick.
Its great that you are admitting fault in this situation. If you feel that you did it just because you don't like the person then you may want to try and let your anger go since it affects you more than it affects him. Also, if anger is causing you to act out that is yet another reason to do your best to reel it in.
You're right, I don't like being controlled by rage. I should let this go.
That's good. Being honest and admitting things can be good for you as well.