"2. If you run through the whole performance in your inner eye, several times over, the actual event will seem already familiar and more comfortable."

Amos is right but I'll go a step further. I'd run through your entire performance out loud, full volume and in sequence if you have a proper place to do so. Nothing helps like rehearsal. Repeat until comfortable.

And drink plenty of water. Just not so much that you'll have to leave in the middle of the performance to find the loo.