Start training muyo thai, learn proper kicks and punches. If you ever get in a fight, you'll probably stay alot calmer since you know your capacity. If you have to, just go low kick punch combo, if its a 1v1, just grab the neck and put knee's all over his face and then slam his head with your elbows. And never underestimate the power of strikes with an open palm, those are fast and hurt alot.
Bas Rutten is a legend btw, started training when he was 21. Never to late ;)