Michelle,
all you can do at this point is to make God the most important person in your life and let Him empower you and Marcy to get through this.

I had the exact same problem with my fiance when my Dad was dying. Needless to say we are not together anymore (we broke up because of it). Maybe it's a sign. How would he react if it was you in that situation? Sometimes it is unavoidable to have to live life on lifes terms.
Doctors can't write hospice orders unless a person has less than 6 months to live. It's a small chunk out of his life but a big part of yours.

It sounds like Marcy is being very graceful through all of this. She is also showing great courage to stay in the fight.

You and Marcy remain in my prayers...