This is a very interesting topic by a professional pianist who once suffered stage fright: Linda Apple Monson.
I think she is American, but in her behaviour she’s more Spanish or from another South-European country.. 😉
But anyway, I like what she says and she’s right: it’s not about the person performing, it’s about the music.
If you deeply agree with this (and very well prepared) the result will be that you are not frightened anymore.
I take note of this.

TED talk on Youtube/Linda Apple Monson