When I was in school, I had to have a come to Jesus moment with myself and find ways to channel my anger and temper. The Bible, church and the Lord helped out there. I surrounded myself with calm and stoic folks. I knew which spaces I couldn't act out in and had to learn to talk to people like I had sense. Playing football and poetry also were later outlets that helped.
I went to anger management as a young adult and have been in therapy for over 20 years. I have also read parts of "The Art of War". Additionally I go to the gym, meditate, and have creative outlets such as writing and painting. I also make sure I eat and sleep regularly and healthy to mitigate any angry feelings.
In 30 years I haven't been into a physical altercation and in 20 years I haven't physically harmed anyone. In just the past year I have reduced negative interactions and arguments by 40%. It's all about control and discipline just as most things are. Your mind is a powerful tool and must be used appropriately