Kennedi, I can really relate to this question. One of my ex-wives wouldn't go near my mouth, ever, because of the sores I SOMETIMES had. (She feared herpes, and with her immune system being compromised as it was, she had reason.)
But I knew--just KNEW it wasn't herpes....and finally got rid of them once and for all.
I believe today that my greatest underlying problem was a mineral deficiency. When I started using a liquid potassium-mineral supplement (extensively, at times), the sores went away within days and never returned.
There will be a START of one every so often--maybe once every couple of years or so. I don't use that mineral supplement today, so when I get a sore like that, I immediately start using colloidal silver--holding it in the mouth, swishing, swallowing. Silver doesn't do much for a potassium deficiency (duh), but it does knock down a lot of viral and bacterial issues in a hurry. And I do take a daily mineral supplement, just not the liquid version I used for a dozen years or so.
Hope this helps.