I have a vacation coming up this Friday for a week. Restaurant meals really throw me off, but I am learning to be more direct and insistent on what I want.
I now have no problem giving my order for "grilled with no breading, fat or sauces, lemon only", or "salad with no croutons, dressing on the side only". If they bring it wrong I very politely look them in the eye and say "I'm sorry, I can't eat that - that isn't what I ordered".
I have discovered that the world doesn't end doing this, and in fact people have been very accommodating in fulfilling my polite but firm requests.
That being said, it is hard to see so many goodies on the menu, and know that those things aren't what my body needs, just what my brain thinks it wants!