My son at 9 years old had to fast 2 days before the surgery and 2 days after the surgery too as it was bowel surgery and he'd already had several previous bowel surgeries. If he can fast for that long, an adult can fast up until evening if necessary, I wish that is all my son had to fast for.
Unfortunately someone always has to be last on the list and they aren't going to be any less hungry or fed up as you are. It's just how it is when you need surgery and there's a list.