I totally identify with what your husband is feeling.  What motivated me, was when I was admitted to the hospital because I wasn't getting enough nutrition.  My husband kept after me, but I gave him the same arguments that your husband is giving you.  When I went for blood work after I had finished my treatments, my oncologist took one look and insisted that I be hospitalized.  I cried and asked if I couldn't just take a pill, but I was hospitalized for three days to build up my nutrition.  That did it for me.  I hadn't been using my PEG, but I did then.  I also started eating yogurt and ice cream and making milk shakes out of Ensure, a banana, and a scoop of ice cream.  I hated the PEG, and I even hated trying to eat, but I didn't want to have to go back to the hospital.