I quit amateur competition because of the nerves. I was overwhelmed by them before every fight and couldn't mitigate them in any way prior to fighting. They would go soon after the bouts started, but the ordeals I experienced prior to that point were too much and drove me away from competing. I competed in other sports without being so nervous, but the violent nature of boxing and being cognizant of the potential consequences made the nerves greater and harder to manage.
I still love to train, watch, and talk about the sport, but no more competition.