Ever since I was a young kid taking piano lessons, I always assumed that I would somehow "outgrow" my performance anxiety, once I'd practiced enough and gained enough experience as a musician.
But it doesn't go away. It will never go away.
Sometimes people are surprised to hear this from me, since I've been making music, often in public performance, for pretty much my entire life- they may be even more surprised to hear it from people like Glenn Gould, Vladimir Horowitz, Pablo Casals, Renée Fleming, and Frédéric Chopin. Fame doesn't rescue you from the fear of failure and judgment, in fact there seem to be several cases where it actually makes it worse. I'm hardly famous, but it makes me start to realize that this kind of fear will always be with me, as long as I'm performing.
Though I'm sure it affects each person differently, I can describe exactly what happens when I'm about to perform. My muscles seize up and get tense, especially in my hands, arms, and upper body. I begin to feel either too cold or too warm. Rational reminders that I have practiced and prepared as much as possible do nothing to calm me down. I begin to feel certain that I will flail madly and make every horrible mistake possible. The organization or person that hired me will refuse to pay me. There will be a reviewer in the audience who will ruin my career with a scathing article. My friends, teachers and alma maters will disavow me. I develop an acute sense of imposter syndrome, convincing myself that everyone else in the room has a more genuine reason to be there, that I'm not a legitimate pianist, because I haven't gone to Fancy Conservatory™ or studied under Famously Mean Instructor© or reached the Magical 10,000 Hours of Practice® (not a thing, by the way) that earn me the rank of Professional.
Recently, I've started using some tools and strategies to survive the emotional agony of playing in front of other people:
I don't seek to combat, ignore, or destroy my performance anxiety- I simply seek to understand how it fits into the larger picture, and clarify when it is or isn't welcome. It will never go away. But it will never define my musical life, either.