Tongue cancer isn't slow growing as far as I know. I don't know the speicifcs of your biopsy but I would not mess around with this.
You have the option to erradicate this from your body and live a healthy rest of your life. I understand your reservations but having this spread or get worse lessens your chance of survival. It will be 1000x more uncomfortable than any treatments you have to go through. You should read through some of the posts here from patients who have had this cancer spread. Sorry to be harsh but I think you need to be a lot more aware of the gravity of the situation.

This is cancer you are dealing with- it isn't something to be reasoned with.