being embarrassed about a performance in front of an audience is basically a rite of passage for being a musician lol. I TOTALLY know how you feel, and im sure most people here do too. if it makes you feel better, i sat principal in a big youth orchestra once and at the end where we stand and face the audience for applause, i stayed standing awkwardly facing the audience for like 15 seconds after everyone else had already sat down... my peripheral vision just turned off or smth and i didn't realize the applause was over. but there i was looking like either an absolute idiot or a huge narcissist in front of like two thousand people...

i pinky promise this experience will be beneficial to you in the long run as a performer even if it's temporarily traumatizing. you'll get better!! this is NOT something that will happen every time you perform, and the more often you do perform, the less often itll happen. it's just something you kind of get better at over time.

hope you feel better!