I agree with Eric. You have ignored three people on the forum that all have some experience with this, who think you have a fungal infection. I don't see any movement from you to determine if that is the very simple cause of your tongue being white. You have been a smoker, so smokers leukoplakia (benign) is also a possibility and when you have been off tobacco for about three weeks it usually just goes away. You have doctors telling that they don't see anhything� this confuses me, since you said your tongue is all white. They would certainly see that. So what's up with that? Bottom line. None of us here are doctors, so we can't tell you anything more. You need to see another doctor for another opinion, have him rule out the simple stuff like fungal, viral, and leukoplakia (which does not turn your whole tongue white but does in spots) and get the answers that will fix things and will calm your mind. These cancer patients here, have done what they can. Please post again after you have another medical opinion from someone that has looked physically in your mouth.