I've had rhinitis (grass pollen allergy) for over 30 years. It used to be really bad, but has got better after I did a medical trial of a new treatment, which is now available, called Grazax. It's a grass pollen tablet which I took for 3 months before the grass pollen season started and which desensitises you. It did work for me. I didn't have any hayfever symptoms that summer, and since then my symptoms have been a lot less severe and can be controlled with over the counter remedied - I use loratadine.
Grazax is supposed to eliminate the allergy completely if taken continuously for 3 years. But unfortunately it is not available from the NHS due to cost - it would cost the NHS £2 a day. It can be prescribed from some private clinics but is quite expensive, around £100 for initial consultation, then £200 a month for private prescriptions.
But to go back to the OP, I haven't noticed any major reduction in my symptoms last summer or this summer, and have needed to take the loratadine and nasal spray.