Talk to General Physician on Oral Thrush

Hi, I have a White tongue since one month after an antibacterial course for a throat infection. I took nilstat drops for it assuming that it's oral thrush. It started to get better but then I had a diarrhea attack and my tongue became white again. I have a slight on and off pain in my stomach and tonsils too.

Can someone please tell me that which doctor should I go to for a check up? I have been to a general physician and to emergency departments but they haven't been of much help yet.