Anthony Sher has written about his stage fright. It is not, as I would have thought, increased adrenaline, sweats, nausea and even terror but, rather
"having four voices in your head. One is speaking the lines, another is mockingly telling the first that at any moment he won't remember them or will faint , the third is reciting a different play altogether and the fourth has the right play but is several acts ahead."
I've often wondered about the psychology of actors - I so easily might have become one had things been different - and, in a more complete sense I have been. I can understand exactly, I think, what he is talking about except, that in my own experience, the voices are different. One says 'I am a woman', the second says 'this is obviously nonsense' while the third mocks both of them and supports the fourth who is speaking the lines of whatever I am saying - as a woman (or as a man - reverse as necessary and without warning.)
I am not being melodramatic or unable to tell what I want. It is a complete loss of sense of who I am, or what I am in the most existential way.