Thanks for writing to H.C.M. for your query regarding difficulty in breathing along with nasal allergy
As you said that you can't breath through your nose, and anti allergic treatment and saline nasal wash is not effective now. Considering your clinical history it appears that you are having some other pathology other than allergy like-
(1) Grossly deviated nasal septum
(2) Turbinate hypertrophy.
(3) Nasal Polyps.
To confirm this a thorough examination of nose is must by an ENT doctor and a C.T. scan of paranasal sinuses
. By this co-relation of clinical finding with report of C.T. scan one can diagnose the nasal obstruction
and accordingly management may be plane.