I'm in my sixth week now, nine radiation treatments and one chemo left. I have lost about 2 pounds through the whole thing so far. I hate eating with no flavor and the various bad tastes in my mouth, but I manage. I've continued to exercise, running about 15 miles a week and going for a weekly bike ride. I chew gum while I exercise and carry water, and my mouth feels mostly normal at those times. It has helped to stay active, I think.
My neck is burning today and I'm starting to get the thick mucous. Still taking very little pain medication, about two hydrocodone/acetaminophan capsules a day.
It all just lasts a long time. Days and days of concentrating on mouth rinses, medicine, neck care, forcing myself to eat, feeling crappy and weariness. Mentally wearing.
It's worth it if it works, and it should. Work.