It's kept me out of prison so far.
It's certainly not good to hang on to it. Neither is it good to let it take over your actions.
You are young, so it may be hard to believe the truth, which is that one can learn to remain calm in situations that might anger others.
its bad to hold onto anger, because that rage inside you will continue to form a little storm, and if not careful, it can explode one day into something you can no longer control. Even if you just write it out or talk it out with a buddy or someone else, you'll feel a little less drained from it.
What can i do
No because sometime you'll just break, or burst. Let it out.