Hello,
Thrush cannot be diagnosed by naked eye and you need to get a KOH examination done. Thrush appears as white patches in the mouth. Usually they can be seen on the tongue, inside the cheeks, under the tongue, and in the back of the throat. I suggest you to get an examination done from your doctor and get a KOH examination of the scrapings done of these white coatings.
Nystatin liquid is used by swishing a bit in your mouth several times a day and then swallowing the medicine. Throat lozenges containing antifungals can also be used. If the symptoms are severe then oral antifungals may be needed.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
I admit it sounds like a serious dose of thrush to me. Keep off sugars until the Doctors work it out.