Peace,
For starters the anxiety of the upcoming surgery has you under stress, and your sleep cycle is off anticipating it. Second, eating something, anything, light soups, etc., as long as you have something on your stomach will improve the anxiety, nutrition plays a big part of this disorder, you skip meals, your anxiety skyrockets, I get more nervous, and make sure that I eat rather I feel like it or not, or I get the shakes, the panic. Your body needs to metabolize food, which helps us, no food, its in high gear to burn energy some other way. Food also helps to relax, not to be confused for comfort, but notice how a good meal sometimes, makes you just want to unbutton your pants and fall asleep? Make sure you try to eat, maybe you cant handle big meals or lots of solid foods now, but crackers, soups, mashed potatoes, etc, are good things to start out on.
Trish