Hello, Welcome Thanks for consulting HCM, I have gone through your query, you have red spot on floor of the mouth, patchy tongue, with white lumps, constant stinging at back of mouth, these all symptoms shows not having proper oral hygiene , for this tongue lesion it can be candidiasis also , so you should go to oral surgeon for proper investigations, cytology , biopsy , to be done if neccessary For this you can do warm saline gargle two - three times a day, go mouthwash chlorhexidine twice daily , on tongue lesion you can apply ointment triamcinolone acetonide paste for relief, and consult dentist for investigations, Hope this will help you. Wish you good health.