Venting is definitely the best start. What worked for me;
1. Diaphgramatic breathing. Google it. Once you practice for a while you can do it in public without anyone knowing.
2. You have to learn, no matter how hard, not to give a shit what anyone else thinks about you. You are clearly more intelligent than most people out there given your writing skills.
By the sounds of it you are still at school, and you will more than likely grow out of it.
Stay strong and I wish you all the best.