Hi welcome to Health care magic forum. As your description describes your problem,is a chronic allergic rhinitis
resulted in nasal block and chronic pharyngitis
I advise you to consult an E.N.T.surgeon, there you will get treatment for for chronic allergy
with newer drug montelecast for complete relief of rhinitis and hence relief of oral breething and chronic pharyngitis.
Besides i advise you some diet recommendations as avoid taking cool drinks, ice creams, cool water , fruits and juices till you get the complete relief. after relief you can use these things . you can find out the things which are allergic to you and try to avoid them for ever.
Wishing for a quick recovery and thanks for calling.