If you feel you MUST have some help or you'll be out of control of your reactions and so forth, there's two things I can mention:

1. This one I can't tell for sure, but a speaker in a class on public speaking recommended, of all things, two aspirins a half hour before the speech. Never tried it; don't know.

2. This one I know works. Get your doctor to prescribe propanolol for you. Take one a half hour before performance.
Now, don't say, "Oh, I wouldn't take drugs! I wouldn't want to be habituated!" or "Oh, I don't want to dull my senses or reactions!" Both of those are inapplicable.
Taking the second one, propanolol does not dull your sense or make you "high" in any way. All it does is prevent the natural nervousness from expressing itself as "the shakes" or that sort of thing.
As to the fear of habituation, that's not involved either. Propanolol is designed (if that's the word) for high blood pressure, I believe it is, but its use for this purpose is well documented and appropriate. My professional pianist wife learned of it in a university class on dealing with stage fright. I'm told that it is extremely commonly used by classical musicians when going to auditions, when the pressure is REALLY on. On the subject of habituation, fear not. So you use it for a given performance. You dind't fall down or lose control of your fingers. So the next time, with that experience behind you, you will have less apprehension. After one or two performances in a given kind or level of situation, you really won't need it, because you KNOW you can do what's needed. Now, supposing you've been doing informal, small-audience gigs and you're suddenly up against a huge house and you're fearful of this new venue, then you may need propanolol's help to control the symptoms in the new situation, until you get used to it. You're NOT going to get locked into its use. I can speak to this from my own experience, and from my wife's experience as related to me.

Dave Oesterreich