Hi abob,
I'm sorry that you and your husband are going through issues with his cancer treatments. Perhaps, your husband should take some time away from the treatments for a while and see what condition he is in. Possibly his body is getting too much medication. That can happen. We are all separate individuals and react differently to medications. The doctor may try and talk your husband out of quitting even for only a short time. However, it's your husband's choice. It's his body and his money!
I wish you and your husband the best. I will remember you both in my prayers.
PML