I'm dubious, especially about the "once and for all". As with most self-help books, probably you could have thought of the bulk of the advice yourself. (The chemical method, which you probably couldn't have thought of yourself--but have nevertheless probably heard of by now--, involves beta-blockers.)
In any case, the term "performance anxiety" is rather an annoying euphemism for what the less pretentious call stage fright, as diagnosed in the great Band song of that name:
Now deep in the heart of a lonely kid
who suffered so much for what he did:
They gave this ploughboy his fortune and fame,
and since that day he ain't been the same.
See the man with the stage fright,
just standing up there to give it all his might.
He got caught in the spotlight,
but when we get to the end,
he wants to start all over again.
I've got firewater right on my breath,
and the doctor warned me I might catch a death.
He said, "You can make it in your disguise,
just never show the fear that's in your eyes."
See the man with the stage fright,
just standing up there to give it all his might.
He got caught in the spotlight,
but when we get to the end
he wants to start all over again.
Now, if he says that he's afraid,
take him at his word,
and for the price that the poor boy's paid
he gets to sing just like a bird.
Your brow is sweating, and your mouth gets dry.
Fancy people go drifting by.
The moment of truth is right at hand:
just one more nightmare you can stand.
See the man with the stage fright,
just standing up there to give it all his might.
He got caught in the spotlight,
but when we get to the end,
he wants to start all over again.
Please don't make him stop.
Let him take it from the top.
Let him start all over again.
Notice, by the way, that the thread-starter here is the self-professed author of the book he's advertising, and that since as of this writing he has a total of three points, it's a pretty fair assumption he came to this site strictly in order to advertise his book. We have a word for this sort of thing in cyberspace, and that word is spam.