Kerry,
I wouldn't worry about it too much at this point. Cancer fatigue is a well known side effect of the treatment and it's pretty normal while the body has been that beat up and add the healing process. Almost everyone has some degree of anemia early post Tx and coupled with malnutrition and other factors it's a long slow process. The narcotics might make a difference but he should be fairly adjusted to them by now.
Just make sure that you keep a log of his food and fluid intake - that's the most important thing right now.

Like Steve, it took over a 1 1/2 years for me to get back to 80-90%. After 3 years post Tx I am almost 100%. The Tx took it's toll however and I do have some relatively minor side effects but nothing I can't live with. Some mild neuropathy, neck muscle spasms, etc. but no trimus, salivary or swallowing problems.

Like Amy I think my wife feared that she would find me dead also but the human body is amazingly resilient.