We have had the best luck controlling most of our allergy symptoms by using a neti pot everyday in the shower. It helps with cold symptoms too. You can buy a sinus wash system from most major retailers, but I don't care for the squeeze bottle type.
We use the neti pot, which looks like a little tea pot, with warm water & 1/2 tsp of baking soda. You tip your head, pour it into each nostril & it flushes out all the pollens, dust & mucus that accumulate in the sinus cavities. It took me a while to wrap my head around putting water through my nose, but it made a huge difference in my allergy/cold/sinus symptoms.
We still have allergy & cold medicine around, but they tend to expire before we use them up, because daily use of the neti pot has really reduced the symptoms. Even the kids use it, because they noticed that it helps more than the pills & sprays.
I have a friend who had constant sinus infections & allergy problems, basically lived on antibiotics, allergy & sinus meds for years. Eventually she had a surgery for her it, but she still had problems. During a follow up with the surgeon, still having the same problems that the surgery was supposed to fix, the surgeon said, maybe you should try a sinus wash system. She wasn't too pleased, to say the least. She started using the neti pot & except for for the occasion cold, she stopped having the sinus infections & allergy symptoms & was able to stop taking the various meds.
It may not help, but it's a simple thing to try, once you wrap your head around the ick factor. Good Luck.