Dry throat white tongue. nystatin given no clear up. dr said not thrush. what is it?

Unsure: Thrush would be the first thing i would think of. These things are hard to tell without seeing you. There are some medical issues such as diabetes i would be checking. Did your doctor look at it or test it?

Need lab work: If you want to know for sure, then you will need a biopsy of the site. Some dentists will do this. Oral surgeons, general physicians, ENT referral----do not give up !