Proper preparation will allow you to turn nerves into excitement and allow you to be spirited in competition.
How to properly prepare
Know your offense from set up to finish
Know your defense to ties, shots, and scrambles if necessary
Know your top game plan for ride, turns, and returns
Know your bottom game plan for escaping common rides and general understanding of defending turns
Create realistic situations in your practice with singlets on, short goes, match simulation, etc.
Practice meditation at practice, at home, at competition.
Proper preparation turns emotional thinking into logical thinking this is what its all about.