Hi, a month ago I had tonsillitis and was given antibiotics. I then got a funny taste and white tongue, Dr said suspected oral thrush but treatment did not work, even fluconazole. My tongue is still white will not brush off and is sore, I seem to be getting a lot of mouth ulcers (I do get these sometimes but this is more often) and inside my lips and cheeks sometimes looks red or almost stings. What could this be? Swab that Dr did for thrush I think came back negative