Hi.. Thanks for the query.. I have gone through your query and can understand your concerns.. As per your complain it looks like you have a dry mouth and bumps at the back of tongue seems to be due to swollen or inflamed circumvallate papillae while white films on lips also seems to be due to dryness in mouth.. Other symptoms may or may not be related to it however all the symptoms can be due to causes like severe dehydration, diabetes while certain Neurological conditions can also be a cause.. Other common causes for dry mouth can be Severe dehydration, Side effects of medications if you take any,Salivary gland dysfunction, Nerve damage supplying salivary glands, Oral infections like thrush,Sjogren s Syndrome etc.. Altered taste is due to reduced saliva flow only as the saliva maintains taste buds and in the absence of appropriate quantities of saliva there is alteration in the function of taste buds leading to altered taste.. Consult an Oral Physician or a Medicine specialist and get evaluated.. As of now: -For dry mouth chew sugarfree chewing gums.. -Drink plenty of water. -Avoid regular mouthwash and use specialized mouthwash that are formulated for dry mouth patients like Biotene.. -You can also instil artificial saliva drops.. -Suck tart candies as it also stimulates saliva flow.. -Take Vitamin B complex supplements.. -Take a nutritious diet and sufficient rest.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.