Legs55. I, too am a sneezer, from late-April through to the end of August. I was practically comotose when a child/teenager due to three doses of Piraton (Chlorphenamine) a day but years ago was prescribed two others: Clarityn (Loratadine) which didn't do much for me and Piriteze (Certirizine), which is brilliant. For me, Certirizine has been a game-changer.
Combined with 2% Sodium Cromoglicate Eye Drops and a nasal spray 50mg Beclometasone - I am a different person, i.e. one with eyes that open and are not swollen shut, one that can breathe normally throughout this period.
I am surprised that your GP won't cooperate; hay fever sounds trivial but it jolly well isn't. Could you try to see another GP at the practice?
Failing the above, tablets can be bought on the internet, reasonably cheaply (9-13p per tablet. Oh, it's one per day.). There are a few puckka firms but be careful of the cowboys. The eye drops and nasal spray are also on general sale, branded and generic so check for the cheapest.
Good luck!