Oh boy do I know what you mean. I get nervous WEEKS before a performance. In the past I've developed ulcers, irritable bowel syndrome, chronic panic attacks, depression, chronic fatigue... you name it. To be honest, what works absolutely best for me is molding my body in the gym EVERY day of the week and eating a one hundred percent healthy diet. I don't eat sugar, refined grains, preservatives, artificial flavors or colors or anything processed. I stick to the basics, fruit, soaked grains, raw dairy products and vegetables. I find that the love and care you put into your own body reflects in all of your activities. (Also, I'm a Christian, so reading my Bible and praying every time I think to helps a lot too.)
Hope this helps!
PS
Try adding hot peppers and spices into your diet, they coat your stomach with protective mucus and release endorphins into your blood stream. Bananas are also great because of the calming potassium.
