Face, how long have you worked at your job? My guess is around 3 months, because I used to be the sameway about my job around that time period. I've worked at my job for around 11 months now, and I'm pretty immune to anything that can happen so nothing really bothers me anymore. So once you get to know everything about your job it will be as much of a big deal to you. Stay in there because I know just how annoying customers can be sometimes.
Btw, I work at mexican food restaurant that has a fast food pace to it. It's hard to explain.