Welcome to OCF! Im so sorry you are so nervous. Please do yourself a big favor and relax! Worrying will never help you to feel better or to change the facts.

This should help you to feel better. Oral cancer tumors do not come and go and get bigger and then subside. They are fixed and will be present, eventually growing.

Any sore which is in your mouth for 2 or 3 weeks needs to be checked by a professional. Here in the US we go to an ENT (ear, nose and throat) specialist or an oral surgeon. The doc will do a biopsy where they remove a teeny tiny piece of the 'sore' and send it out for analyses at a lab, the results will be back in about a week. The biopsy is the only way to determine for certain if the tissue is cancerous or not. From your description it does not sound like what you have is cancerous. Go get checked and then you can relax knowing you are ok.

Good luck!