Recurrent apthous ulcers of mouth can occur because of various reasons such as nutritional deficiency, sharp teeth, consumption of chronic irritants like tobacco/beetle nut, hot beverages, autoimmune conditions etc. Treatment depends on identifying cause for your problem. Presently you need to take symptomatic treatment like painkillers and local gel application like dentogel
Next Steps
Consult nearby ENT specialist for confirmation of diagnosis and appropriate treatment if required