I was a working professional musician for a number of years. It was this that launched the business from which I have at least temporarily retired.
Because I did a great deal of solo work, "performance anxiety" went with the territory. What I did to overcome it was to deliberately force myself to do it more and more.
My basic personality is in fact extremely shy and to this very day I do not basically enjoy crowded situations or large groups of people. In my secondary school years my shyness literally became a handicap.
If I were to get back at the keyboard of a large concert grand piano or sit at the console of a very large pipe organ these days, I can guarantee you that I would again go through a living hell for a period of time until I realized that sitting on that bench was not going to kill me.
When I was dealing with audiences, what I started to do was to pick out a single person in the audience and do my narration mentally as if I was directing it to that single individual. I also started to direct my music mentally as if it was being done in my living room and was being performed for a single individual. When I was studying both Law and Music in College I had to take a ton of Psych courses. I spent some time in the office of one of my Psych Professors on just this very subject. He was a great guy and because I had to perform as a soloist (by virtue of what I played) he gave me a ton of tricks to do which would assist me in overcoming this kind of anxiety.
The best thing I can tell you is that if you work on it, it will definitely get better and all of a sudden, even if you're a shy person by nature, you will begin to be able to deal with situations which create any form of performance anxiety.
My friend, believe it or not there are many very famous people who have shared your type of anxiety.
My only suggestion is to try everything you can to avoid using a chemical solution to a non-chemical problem. As a musician, I discovered that medications that would work to calm me down, would destroy my performance. In the bedroom, these same medications in some individuals have the ability to cause physical performance problems, and that would only make your feelings far worse.
Feel free to PM me and I will do what I can for you on an individual basis. Im not a psychiatric professional, but, I am a total basic introvert who sat on a performance stage at the Hollywood bowl many years ago performing an extremely technically demanding classical piano composition with an orchestra dressed in black and myself in a spotlight in a white tux. My friend, I am here to tell about it and if I relay to you personally how I survived that and prospered because of it, it may help you a great deal.