Shari,
I am so sorry. I have to say your question about what to do for his remaining days tells me you understand the role of a caregiver in this final stage. I'm not in quite the same place, but I have worked in cancer care for 20 years. Many families believe that their doctor will tell them when its time for hospice. In fact, doctors wait for you to ask about hospice. They are totally tuned in to making the time at the end comfortable and meaningful and will be the right partner for you. They can help in ways your oncologist cannot. I would suggest you talk to them and consider this option.
Your love comes through in this message. I hope you both find peace in the coming weeks and months.
Susan