I had one...and I agree, it was awful. I was in that morning for sinus surgery too (my doctor was big on sinus catheters before the surgery to do tobi rinses). So I get the catheters put in, go home, get in bed, (and that is a pretty painful and bloody surgery) and get a call saying don't eat and come right back to the hospital. I get there and wait, and wait, and wait. Finally at 9 pm they tell me that it's a no go. Since I hadn't eaten since midnight the night before I had no reaction other than "Can I please eat!!".
Keep your head up. Your time will come!