1) Do not stop the trimethoprim/sulfamethoxazole on your own — first confirm with the doctor who started it whether the full course is still needed. 2) Start a simple oral care routine: clindamycin-free saline or sodium bicarbonate rinses 3-4 times a day, gentle tongue cleaning with a soft brush, and stop smoking, tobacco, pan masala, very hot and spicy food. 3) An antifungal (clotrimazole mouth paint / oral candid gel) applied after food is usually what settles this, but it should be prescribed after a doctor actually looks at the tongue. 4) Get basic bloods done: CBC, serum B12, folate, ferritin/iron studies, and a random blood sugar/HbA1c — an undiagnosed high sugar is a common reason for recurrent oral thrush. 5) Keep eating: cool, soft, bland food (curd, khichdi, banana, milk) and plenty of fluids so you do not get dehydrated. 6) You can consult me on Practo for a detailed online review of your photos and your current medicines, or if you are in or around Miraj/Sangli you are welcome to see me in person at Synergy Multispeciality Hospital, Miraj, where the tongue can be examined properly and the blood tests arranged the same day.

Word of caution: sulfamethoxazole can rarely cause serious skin/mucosal reactions. If you develop fever with a rash, blisters or peeling anywhere on the skin, ulcers in the eyes or genitals, swelling of the lips or difficulty breathing or swallowing, stop the tablet and go to an emergency department immediately. Also see a doctor without delay if a white patch cannot be wiped off and keeps growing, if there is a non-healing ulcer or lump on the tongue lasting more than 2-3 weeks, or if you are unable to eat/drink at all. Please do not self-medicate with steroid mouth applications.