Kerry,

As everybody says, fatigue is normal. Mine got worse for four weeks after the radiation, when I thought I should have been getting better. I absolutely had no energy - the only times I went ouside was to go to the doctor, and then rested from that until the next visit.
I did not have a tube for food, so I had to spend most of my awake time drinking liquid yoghurt through a straw very slowly (it was the only thing that would go down and most of the time stay down).
Two years post-radiation, and I still have to pace myself - or maybe I am using it as an excuse? Might be I'm just getting old?
Give him time - and encouragement, but try not to push him. "moderate exercise" means very, very moderate. He probably needs a half-hour rest after a walk to the bathroom.
It'll get better
Leena