By trying everything, I'm guessing you've taken antihistamines such as Claritin and Zyrtec as well as decongestants like Mucinex. If those did not help, you should consider allergy testing to see what you are allergic to. If severe enough, your allergist can start you on allergy shots.
I have done allergy testing and they had decided that im not allergic to much else but some foods ( such as nuts and apples) which i stay away from so they decided that allergy shots were not necessary.
Perhaps Nasalcrom (cromolyn sodium) would be of benefit.