I have dust mite allergy. It means I can't wear my big fluffy dressing gown anymore! Really wish I could as the evenings get dark and cold. Theoretically I could if I boil washed it after every wear, but it's not practical and terribly bad for the environment. Fleece is warm and sweaty, so perfect breeding ground for the little buggers.
Also can't drink alcohol. I don't miss that, just wish there was a better range of drinks out that aren't all sugary or fizzy. No one has ever invented a drinkable no alcohol wine.
What have you been sad to give up because your body hates you?