Tee hee. I've heard a lot of things said about me, a lot of them bad. But you can't let them get to you- By doing that, you're letting them win because your reaction is proof that they got to you. Ignoring them is REALLY hard, believe me, I certainly know, but it's something you have to do.
Since you're 14, that makes sense too. Your mind and emotions are in a flurry and you tend to act on impulse. That's part of growing up. But punching people and cutting their hair isn't really the best way to settle things.