Hi.. Can understand your concern.. As per your complain it seems that you have a condition known as BURNING MOUTH SYNDROME in which there is burning sensation on different mucous membranes of mouth and it is more common on tongue while can also effect inner lips cheeks palate etc.. I can occur most commonly in case of Dry mouth but at times it can occur without any underlying cause.. It can occur due to a number of conditions like nutritional deficiency, thrush,herpes ,Sjogrens syndrome, HIV,uncontrolled diabetes, denture wearing, mouth breathers, medications like high blood pressure medicines etc.. As you have also explained that there is a coating on tongue it can be possible that there is fungal infection known as Thrush or candidiasis which is causing you formation of layer which can be cheesy in appearence as well as on removal it leaves a raw and inflammed surface behind.. As you find taste buds also affected there are a high chances that it is all happening due to Dry mouth.. I would suggest you to consult a dentist and get evaluated and in case if you have a fungal infection along with dry mouth oral antifungal medicines ,nystatin mouth washes and antifungal lozenges and drops can help.. Adding probiotics to diet like Yoghurt and garlic can relieve.. For dry mouth saliva stimulants like sour candies and sugar free chewing gums and lemon drops can increase saliva flow.. Saliva substitutes containing methyl cellulose can be instilled in mouth for lubrication.. Drink plenty of cold water to maintain hydration and reduce inflammation on tongue.. Sucking ice pops can help.. Salt water rinses can be done.. Avoid antimicrobial mouthwashes.. Hope this information helps.. If you find the answer helpful kindly write a positive review and click on found this answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora.