There’s a lot of good advice here already, so I’ll just add the potentially expensive (depending on insurance) next step: allergen immunotherapy. I’m about as allergic to dogs as you are, and some of the advice I got was “why not make them an outside dog?” — first of all, hell no, they’re family, and second, I lived in an apartment at the time, so that was impossible.

The immunotherapy, or allergy shots, starts with the tests others mentioned. They can do skin pricks or blood draw, and to save you a lot of misery, I suggest the blood draw. Then you get vials drawn up that effectively tincture allergens over time into your body for about three-ish years, so this is a time commitment.

Some advice on allergy medications I’ve received: avoid Claritin and Benadryl due to their links to dementia in long term use, try Zyrtec and Xyzal to see which works best (Costco/sam’s has the best value for these).

A higher MERV filter in my air unit, based on what it could handle, and an air purifier helped me a lot.