Used to suffer heavily from hay fever. Started around when I was 12, then when I moved to Oregon, USA(lots of trees here), it just went crazy.
Many years ago, my boss saw me suffering from the pollen attack, and told me what worked for him: He stopped taking medicines. It just went away after a season or two.
All allergy medicine ever did for me was make me drowsy, so I quit. Sure enough, over the next year or two, it just went. It's been so many years, I don't even know how many, but the pollen has not affected me the way it used to.
Occasionally, I'll get runny nose and/or sneeze. But then it stops. Immediately.
You can try it, but if you die, you didn't get this tip from me.
P.S. I was going through boxes of Kleenex to blow my nose, and to the point my nose started hurting from skin turning red & raw. Then I'd ran out of Kleenex, so I get toilet paper, and they were even worse. Ever since I switched to the lotion applied Kleenex, that problem I also haven't experienced. Amazing product, my nose saver.