Argh..I'm sorry to hear your husband is not responding to treatment. Have you looked into this?
Bone marrow transplant?
Stem cell transplant?
You mentioned your husband gets "too sick" between treatments. In what way does he get sick? Is it due to the actual treatments?
Tell your husband that absolutely no one's life is spent waiting to die, there is a purpose, a meaning or transition that applies to all of us. Never give up the good fight!