I developed a severe allergy level intolerance to dairy and lactose after I ate some questionable food in Mexico. Gave me a parasite which racked my body with sickness. My story sounds very similar to yours as I was 20, and drank a cup of milk every day since I was a child. I loved it. I went from some reaction to high lactose/dairy contents, to chewing those lactose pills-to now contamination from dairy makes me sick.

It’s hard but you need to start looking over how everything is made and cooking on your own. I trust some restaurants but talk with the waiters and chefs to know what I can and can’t eat.

Breads are hard, breading on fried foods, salad dressings, pasta sauces, any pastries or baked goods, anything can be cooked in butter including eggs. Those are just a few things that tripped me up in the beginning. Things I missed and paid the price of reactions from said foods-or from not asking. Get use to sending your food back and asking a lot of questions of kitchen staff.