Kerry,
All the advice on here is excellent but varies widely. Makes it tough for you I bet. What does Stephen say? Is he still in horrible pain that is keeping him in bed all day? Is he still on heavy pain killers? Gary is correct about the fatigue, it can be debilitating, is this what is going on with Stephen? You stated that Stephen said he doesn't feel he's pushing himself enough, that is what I based my answer on. I remember reading a posting from Danny (digitex) when I had completed treatment and was spiraling into a horrible depression. Danny talked about how all he wanted to do was sit at home on rather then do anything. That was how I felt for awhile. Danny also posted how he began to take a walk every single day and how it helped. I started doing the same thing, and it did more for me then any medicine did. A good start for Stephen, I think, is to at the very least get out of the bed. Take a daily shower at a minimum, if possible, get out of the house once a day.
I hope it gets better for you soon. The reactions to treatment are so varied that it's hard to know which advice to listen to. Maybe you need to just keep trying all of them until the one that is right for Stephen shows itself.
Minnie