I was once told that anger is generated when something or someone stands between yourself and a goal.
I have often found this to be a good way of identifying goals that were unknown or hidden, even from myself. For instance I felt resentment toward someone and this weekend when I was trying to think of "why" I realised that my primary goal is to feel worthwhile, an asset to my family firstly and then to humanity, and he had, by his unkind words, tried to "convince me" that I'm not. It obviously wasn't his blatant intention but nonetheless that was the result.
I believe that if I succeed in finding my worth in the truth of what God says, that people's opinions won't devastate me as much as it is more difficult for people to come between a vertical relationship with God than a horizontal relationship with man. If that makes sense?
In the meantime seeing the problem for what it is makes it easier to cope with and face up to and perhaps find a constructive solution.
So next time you're angry, take a moment, you could find out something about yourself that you never knew. Step back and look at "why" and your goals may become more obvious to you.