I need to know how old are u, are you a female or male, is this the first time u feel this pain inside your mouth. What do you mean small pores on the inside of your cheeks. Do you feel the pain on eating only or between eating as well. Are you allergic to any food. Do you have a geographic tongue. Until you answer my questions please use topical steroid oral rinse (1x5/day) but if you need a prescription, then you can use instead a chlorhexidine digluconate mouth wash 1x3 per day until resolution. If the lesion continues then do a blood test to check for serum vitamin B12 and ferritin level. Send me a photo of the lesion if you can.
Its either a virus like a canker sore or a allergy to a food you ate.