Falcon - sounds to me as though you're doing all the right things. And I'm so glad to read of the
HPV+ status!
You're not complaining (as I certainly did!) about the rads, which I take to be a good sign. It's a tough treatment, no question, so please post any and all questions about any of it - side effects especially as there are real experts here on how to manage those.
Assume you'd visited a dentist and gotten fluoride trays prior to the radiation (?). Anyway it's something to ask about if not.
Good luck and courage - from all of us.