Wow, I'm glad you are in remission. I assume they did a biopsy of the tumor and it was hpv 16 positive. Did you have any idea you had HPV 16 before tour diagnosis? What stage anf symptoms did you have?
Most head and neck cancer from HPV occurs in the tonsils or base of tongue area, but it's all connected (nose, mouth, throat) and hpv seems to sometimes manifest in areas where there was seemingly no contact. If there's a passage from the site of infection, I guess the cancer can occur there.
Honestly, I don't know enough about nasal cancer to really provide any useful information. It seems like it's the luck of the draw with hpv. The medical community can't seem to do much with it either. It's pretty terrible.
Anyways, I hope you dry in remission and keep improving. Hopefully some of those harsh side effects go away or get much better in time.