I am so sorry things aren't looking better for your husband and you. I think Snoopy had great advice. I would also make arrangements to renew the marriage vows as soon as possible.
I know how lonely it can be even if there are others around you. Yesterday was my birthday and I didn't even feel like acknowledging it since it is my first without my Mom who passed away not even five months ago. Like you,
my children are grown (one as a Senior in high school; and one a Senior in college) so I don't feel quite as bad not being able to get into the "Christmas Spirit" either. I put the tree up....but that seems to be as far as I can go. I am not sure that I can hang the stockings on the mantle knowing one is my Mom's. I miss her so much.
Talking to the deacon from my church (who was also the Deacon for the hospice service my mom had) really helped me a lot. It is important that you acknowledge your feelings and let them out. I used tell my husband to watch Mom for me and then I would get in my car...drive to the nearest church parking lot (church was always locked) and sit in my car and scream, cry, yell, etc. I always felt better afterwards. It's important that you have someone to talk to as well. A lot of times, I would come to these boards and just vent.
Please know that my prayers are with you, your husband, and entire family during this most difficult time. And I know I keep saying this, but I really urge you to call in a hospice service. They are so helpful and kind not only to the patient but the entire family as well. They truly were my "Angels".