So sorry your husband is having a tough time. Implore him not to give up. This was only his first crack at it. He still has so many options..different chemos, different regimens. My mom became very ill with her chemo as well and her doctor was able to adjust the dose and the time intervals between chemos to make it tolerable for her, and even at a reduced dose, the gemzar kept her Stage III pancreatic cancer stable from August thru February of this year. She agreed to continue as long as she was able to have more good days than bad..quality over quantity. In fact, during her good weeks she was able to go play bridge and have people over for dinner parties. She loved to entertain.
In my mom's case, she finally elected to stop in February when she no longer was able to bounce back from chemo and had no good days between chemo, but her cancer was still just Stage III when she stopped. Scans showed no spread other than locally and no change in tumor size. Unfortunately, when she started out, the cancer had already beaten her down so far that she was kind of behind the 8-ball out of the gate. She was also 80 years old.
Please give your husband my best and tell him there may be many better days ahead. He has to give the doctors more than one chance to help him fight.