I was diagnosed with Celiac's in 2008 and have found the best way to figure out if I can eat at a specific restaurant is to call ahead and ask for the manager. I explain what I have and ask if they feel confident they can serve me within a 20 ppm tolerance. I have found some restaurants that have gluten free menus will NOT commit to that, but alot of chef/owner one know there ingredients and kitchen well and can serve me even if they don't have a menu.
I would suggest getting a grocery guide, check all your medications with your pharmacist and just take it one step at a time. It is scary but you will feel better the longer you are on the diet.