The "month of recovery for each week of treatment" refers to radiation. Most of us have had adjunctive chemo so it might be a small factor in shortening the healing time without it.
Joe should start to turn the corner between 6-8 weeks, then he will start improving gradually. I started getting my sense of taste back about then. One must be very patient - it is a long slow process. About 2 months or so I was pretty much taking care of myself. My wife was still doing the shopping because the immune system takes a long time to recover so you have to avoid public places.

I lost 61 lbs and was lucky to get that many calories in as Joe gets. Healing will be enhanced by 3 things. 1. pain management, 2. adequate calories and hydration and 3 infection control.

Try to stay in the "now" and do the best you can on a daily basis.