And what jontherobot said:deal with the causes of your emotions
Only you can know whether suppressing the emotion is gonna work for you. It might lead to a whole load of other issues which you're not prepared for. As my answers from the NF angle might. So use em all and let us know what happens.Like a cheetah, you're built for it or you're not.
I guess conscious development over a long period of time might work. Or drugs.
What I suspect is happening is that you have these issues in your head which need resolving, but they are being precipitated by some combination of ahem "difficult" customers who for some reason that you also need to figure out, are hitting your buttons.
kyuuei has an interesting solution: join the army first, so you can get used to being in danger ALL THE TIME and not care. It sounds like an antidote, a catharsis, for NF-ness. Then, when you've developed that method of dealing with stuff, go back to being a waitress