A couple of years ago, when my doctor suggested I go off wheat (which was sooooo hard), he said "food isn't pleasure, it's fuel for your body". Now I'm not saying that when my husband is eating a big bag of sour cream n' onion potato chips and a Coke that I don't get a little pissed off that I can't share in the fun, but I've tried to find other things that give me pleasure besides food. Like a long hot bath, renting a movie, playing scrabble and scoring 400 (I've played ALOT of scrabble as a result of this strategy). Anyway, I try to think of meals as "fuelling up" rather than times for pleasure, and it seems to help!
By the way, do you have recipe books that are gluten/dairy/egg/sugar free? And were any allergy tests helpful for you, or do you just know right away with hives etc?