If you take Benedryl does it help?
I have allergies to anything you might inhale - dogs, cats, horses, ragweed, pollen, mold, farms in general... I get the extra bonus of allergy triggered asthma, I get the sinus thing with a steady drop in lung capacity.
Antihistamines help and become necessary in the spring and fall. In Denver, it was the annual cottonwood shedding that sent me to hell every spring. Bronchodialators like ventolin or alupent become necessary and during peak times I occasionally need inhalation steroids for a couple weeks - especially to recover from a cold or similar.
Change your venue (go to Arizona for a few days) and see what happens - you'll know then.