Wendy,
My heart goes out to you. I had the roughest time when my husband went thru rad/chemo as I hadn't found these boards yet and only had friends and family to talk to but no-one really with experience...my recommendation is to do everthing you need to keep him on track...be as calm as you can and strong as you can throughout...you will be the rock that he can and will rely on. Our common sense will guide us to help get thru this the best we can...in baby steps and repetitively.
I would track EVERYTHING going in and out of his body and pester him relentlessly to the best my sanity would allow...kindof feeling like every single day was monumental in his getting thru this!
Prayers are with you!