My partner has a white tongue and a crack straight down the centre he has been to doctors who have given him medication for oral thrush this hasnt cleared it up at all he has had it for about 5 month he also gets dry mouth he told me he had test for diabetes about a year ago what else could be causing this !!!
Thanks for your query, I have gone through your query. The fissure tongue or cracks over the tongue makes the tongue more vulnerable to fungal infection like candidiasis. Since you are giving history of Chat Doctor.  You have to get your blood sugar level checked to rule out diabetes where there are more chances of candida infection. Continue the antifungal