You are probably suffering from allergic pharyngo-rhinitis
, i.e., an allergic condition affecting your nose and throat.
You should avoid the triggers of your malady, i.e., avoid exposure to dust, smoke, cold
And yes take lots of water ( not from the fridge, ofcourse !!!).
Many a times the culprit is the tonsils.
So get a total and differential count of blood done, and also a throat swab culture and sensitivity test.
Do warm saline gargle.
Take citrus fruits.
Avoid spicy food.
And don't you worry, usually a course of antibiotic and antiallergic does the job.
Yet, consult an ENT Specialist
, he/she will examine and give the best advice.