Early morning throat dryness and thirst.

I am suffering from early morning throat and mouth dryness around 4 to 5 am from month of November. I consulted with Doctor  and went through a urine test for blood sugar level but it was normal . I took medicine for one week and I got relaxation but after few days it again started creating disturbance in my morning time. I would like to inform you that I am also suffering from a prolong nosal blockage which was happened in year 2011 after a viral fever so  Due to this I am unable to smell properly.Sometimes I can smell whenever my nosal passage gets clear or after a cold. I also suffer from frequent cold after 1 month or 2 month . Now my question is where I have to consult for this problem. As I went through internet for this problem it's symptoms are matched with different different disease like throat infection , prediabetic situation or sinus problems. Kindly suggest me the right specialist with right treatment.