Nancy-
How long did you eliminate prospective allergenic foods? My
experience is that it took at least 3 days to get a noticeable
decline in symptoms, and then about a week to be almost gone, maybe
10-14 days even.

You're "bad" feeling may be your own withdrawal (caffeine, other
foods), which can also last for 2 weeks. Some people also crave what
they're allergic to, setting off some endorphins when they eat the
food.

My daughter had terrible problems with a group of foods called
salicylates, which includes berries and nuts (and some other foods-
like spices, grapes, oranges, apple peel) she had much trouble going
to sleep and eating. My eating corn (and some Calcium OJ) led her to
throw up daily. It took me months to figure that out (I think she
outgrew the spitting up by 11 months).  More info  on sallicylates
(and links) at
http://allergies.about.com/cs/salicylate/a/aa040300a.htm