I have to tell you that the best thing my husband did is to KEEP WORKING! He took 3 weeks off to heal after the surgery, but worked every day of rad, and took his laptop to work during chemo. Granted he was exhausted when he came home in the evening. I would pick him up from the train, with a green protein shake, every evening. Not only did he need the nutrition, but also the fluids.
Don't let this thing beat you!