I've had on/off blocked ears for 10 months tiredness and sore head also. my gp can't see any physical cause. decongestants and nasal spray don't work.?

Seasonal allergies: The most likely cause is seasonal allergies especially if symptoms have been going on for several months. Try taking Claritin (loratadine) daily as well as oral decongestants. Followup with your family practice provider if symptoms continue.

ENT: With this sensation fo blocked ears without any obvious cause, it might be beneficial to have an evaluation by an ear, nose, throat doctor. They also have machines that measure the compliance and impedance of the ear drum which can help with diagnosis. Best of luck!