Sir, I Am Suffering From Mouth Ulcer In Inner Area

Sir, I am suffering from mouth ulcer in inner area of the cheeks, lips , tongue since long. It happens very frquently like every 30-60 days. I have tried all medicines like Becosules, Mucopain gel, Hexigel, Candid gel, zytee gel. I get some temporary relief . My innner are of the cheeks are like white color, and i am getting sharp pain while eating salty or spicy food. Please tell me some permanenent solutions to get it well.