Eating local honey can help, or if it's really bad, try going to your GP for something stronger than a standard antihistamine. Also, put a bit of Vaseline on your nostrils at night (or you can buy specific products) - it stops some of the pollen being inhaled as it sticks to the jelly. And last thing at night and first thing in the morning, maybe middle of the day if you're not wearing any makeup, try those anti-allergy wipes: sweep over your face, neck, hairline and around ears.