Before using any drugs, you might like to try some 'old fashioned' non-drug remedies - like a Neti pot or the modern equivalent, Fess Spray. Basically this is about flushing the sinus cavity with either lukewarm water or saline - which flushes out the irritants and relieves pressure.

Another thing you could try is a (very) warm facewasher over your eyes and nose. This is magic when you're having sinusy type pain and pressure. You'll be addicted to this in no time LOL.

Finally, don't forget that hayfever is about total load of allergens - so drink lots of water (to flush them out of your system), keep your house as dust-free as possible and stay indoors on high-pollen days. HTH, I hope you get some relief soon.