Food allergy ( for the chocolate part.)
as for the lactose intolerance. it will give you bloating, mabee even diarrhea. you can still have milk products that are lactose free, lactose free milk which is about the same price as regular milk, and when you want to eat anything containing milk (chese, etc, get some Lacteeze pills at the pharmacy and take as indicated on package, there great.
also think of mabee switching from regular milk to rice or soya milk, unless you are allergic to any of these 2 products, they are great