Hello, I can understand your concern. It seems plausible that your stomach might not be tolerant to the food items you are describing your stomach is not digesting well and causing you troubles. There might be a substance common to all these food items such as fat that your stomach is unable to digest and causing you troubles. For example, a lactose intolerant person cannot have milk in diet. If he does, he suffers from diarrhea and flatulence. I would advise you to avoid these items for some time and see if your stomach problems resolve. In addition, the mouth ulcers you are describing seems to be related to the stomach upset you are suffering from. Stomach problems are capable of causing ulcers in mouth. So when your stomach problems will resolve, you will not suffer from mouth ulcers and biting tongue anymore. Till then, to find relief in already developed ulcers and for their faster healing, you can apply topical Benzocaine gel (Mucopain) to the ulcers 3-4 times a day. If you will apply this gel 5 minutes before meals, you will not feel pain and burning in ulcers while eating. However, if your problems do not resolve after changing diet, you should see a Gastroenterologist for physical examination and further investigations regarding the problem. I hope this information helps you. Thank you for choosing HealthcareMagic. I wish you feel better soon. Best, Dr. Viraj Shah