That is a bummer! I can't imagine not being able to eat healthy fruits and veggies!
Why are you fasting in the first place? Is it a spiritual thing or is it something you're doing to try to get fit and healthy?
Either way, how about being creative with your fasting? Like a Water Fast only? or a liquid fast? or maybe a pastry fast? Just because you're allergic to some things doesn't mean there isn't a way around it!
Cheers and best of luck in your fasting!
Drink plenty of liquid because you're body will need it more than ever!