Victory,
I know it can seem very frustrating and limiting to find things to eat. I am on my third that I nurse and deal with this. And I nurse typically 18+ months. But . . . it does get easier as you go and you learn different things.

Almost any meat is fine and the protein makes good rich milk so don't limit yourself there. Most fruits and veges are fine and obviously healthy for you as well. The only caution is to watch for a reaction to the cabbage family - they can cause gas or colicky type symptoms. Legumes are healthy and a good source of fiber but don't over-do it on them either cuz of the gas issue.
For dairy there are substitutes - Smart Balance Light is both gluten and casein free - only one that I know of. IF your baby can tolerate raw goat's milk that is good for you to use and drink in place of cow dairy milk. And then you can use that to make your own yogurt (plain yogurt is essentially same as sour cream), cream cheese, ice cream, etc. If not, you can always use rice milk for when you need milk. Not really anything you'd want to drink but acceptable for cooking purposes. Stay away from soy milk products. The hardest thing to find a substitute for is regular cheese. Haven't found one yet so go without most of the time or have a VERY occassional splurge.
For eggs - if you can find them - try duck or turkey eggs. My boys can tolerate duck eggs in place of chicken eggs. Otherwise there is an egg substitute that you can use in baking and such but not for "making eggs".
Check the gluten free thread for ideas on gluten free sustitutes.
If your child has true allergies they will show up on the test regardless of frequency. If it is just intolerances they may not show up, or show up with less intensity. That is good. My naturopath said that babies digestive tracts are "porous" for the first two years so that time period is most critical to feed properly. If there is no ongoing irritation then as they age the intestinal wall becomes more "normal" and they are less sensitive and can have these foods on occassion. In fact at that point if you follow a nourishing traditions/makers diet type model they may be able to eat about anything.
Hang in there - it can be done.

And it is SOOO worth it to make the sacrifices to be able to nurse your baby and see him healthy. Besides, if you think it is hard to find food for YOU to eat while nursing, imagine trying to find food that he can eat directly.
Lori