slight health un-scare :)
A little further reading reveals there's a condition called "oral dysplasia" which can be a cancer precursor but isn't malignant in itself, and it looks a LOT like the little red dent I've got. It sounds like there's a serious chance this is "that thing we caught early enough that nothing actually bad will happen beyond some dental bills." That's at least the magic feather I needed to continue about my day... after a nice nap to drain out the last of the panic juice.