Talk to General Physician on Tongue Ulcer

My mother recently had hystrectomy procedure (1.5 months ago). Due to some after operate infection her healing procedure went slow but now Alhamdolillah stiches are removed and healed. During that period she was on antibiotics advised by concerned surgeon (for may b 30days on and off) recently she had developed severe tongue ulcers (pic attached) and now its been 11 days. In starting 3 days, we used nilstat and somogel, no improvement then 3 days Kenalog gel; 25-30% improvement (stopped on my local friend dr advice because he was of opinion that steroids can't be used for longer period) then 4 days betnesol improvement. From yesterday started Revomet plus gel. she is taking folic acid as well. Scenario is, she is having pain in ulcers normally feel severe pain while eating and drinking water even.

please guide me how to treat these ulcers and direct me to any ulcer specialist Dr so that i can consult. Need help in this regard