You are probably suffering from Rhinosinusitis.
In this condition, there is a persistent postnasal discharge which trickles down to your throat and irritates; it usually leads to pharyngitis
, thus causing throat pain.
Take warm saline gargle.
Use a nasal decongestant drops.
Avoid cold foods.
Stay away from AC rooms.
You need an antiallergic and a cough
Get a total and differential count of blood done; one has to be on the lookout for eosinophilia
Get an X-Ray PNS done.
Take the reports and consult an ENT Specialist
And don't worry, it will be cured.