Tick. Thud. Tick. Thud. Can the audience hear that? The sound of my heart beating syncronously with the metronome I hope not. Because all I hear is the simultaneous thud/tick of nerves. Dont show your nerves
Can the audience see that? The sweat that's accumulated on your palms I hope not. Because all I feel is a cold slimy instrument in you hands. Slipping like butter.
Can the audience feel that? That frantic look you're giving everyone I hope not. Because angst and apprehension don't go over well with spectators.
Just don't show your nerves. Relax. And take some deep breaths.