Inside of my mouth kn my gum is a sore its white and has beenthere for the past few days its hurts like a cut not very sore help plz?

Apthous Ulcer?: By description and location it sounds like an apthous ulcer. We are not sure the cause (maybe an overactive immune system) but it is linked to stress and those who get them often get them again. There are limited home treatments (l-lysine can help as can multi-vitamins) as well as some prescriptions. They generally are worse the first days and last 10-14 days. If beyond that see your dentist.