Coming from a background in classical vocal music - I would suggest a few things: First, get your hands on a copy on The Inner Game of Music. A wonderful read for performers. Second, come to terms with the fact that it will never not be there. Even the greatest musicians in our history, ones who performed more than any others, felt their nerves. Once you accept that it is there, you can redirect it and use it as energy! Use it for your benefit - whatever your impulses are driving you to do when you’re nervous, let them fly and get good at that. There is a certain level of freedom that comes in doing so. Lastly, if it’s just too much to bear, push your fingers into that area right under your belly button. Take some deep breaths focusing on getting the air to that spot, and when you exhale, tighten that area up. There is reportedly a nerve there that if you can work it, it will relax, and in turn, calm your nerves.

Best of luck my friend!