It sounds like your Onc recommends oxiaplatin as far as the chemo goes. It doesn't always cause permanent numbness but it certainly can. Are you comfortable with just stopping where you are?
It's a tough call that only you can make. There's no guarantee that doing the chemo will cure you forever and there's nothing to say that you're not in the clear now. Regardless of what you decide, I would look into dietary changes to lessen the possibility of a recurrence if you haven't already.