I've been diagnosed Coeliac for over 40 years OP, welcome to the club.
Some random recommendations.
Get used to self catering holidays. A hotel's ok for a night we find, but no longer. On the plus side if you rent a villa or apartment, you'll have a lot more space to enjoy.
Spain and the Canary Isles are very good for Coeliacs. The CEO of the Mercadona supermarket chain's daughter is a Coeliac, so their labelling is excellent. One of the Canary Island supermarkets, I forget which one, used to print all the price labels of gf products in a different colour.
You can order gf burgers at McDonalds in Spain and Portugal.
A couple of tips if you're barbecuing this weekend. The Bratwurst in Aldi and Lidl are tasty and gf. Aldi's Marmite equivalent is gf ( don't use Marmite).
I'll be making a German potato salad that's gf this weekend. Cooked potatoes, chopped tomatoes, onions, cucumber, green pepper, chopped German salami ( from a packet, not a deli slicer) and Hellmann's mayonnaise.
A quick recipe for you that people will think you've slaved over for hours: Pork fillet medallions in a Dijon mustard and cream sauce ( EDITED TO ADD Maille Dijon mustard is safe). Fry the pork fillet in a little butter. Sauce is a pot of single cream, a teaspoonful of Dijon mustard, a twist of black pepper and a slosh of brandy. If you don't have any brandy, add a quarter teaspoon of sugar. Don't over heat the sauce or it will separate.
If you wanted you could roast cubed potatoes, onions, peppers, mushrooms in olive oil, garlic, rosemary and thyme to go with it, and a little rice to soak up the sauce.
I find Asda's sliced brown bread to be very easily digestible, and it's very reasonably priced too.
Good luck!