Hey hun, this is so awful for you and your husband. I wanted to say something to you to that I learned when I was caring for my Mum in her last months of cancer and that is when you are caring for someone like you will be, make sure you do something nice for yourself every single day. Seriously you'll be putting everything you've got into your husband because you'll want to but please do something for yourself daily. I know this sounds mad but it will keep you sane. My thing (I was young) was to do my makeup before I began my day at the crack of dawn. May sound silly but it worked for me.
If you want your hubby to see you slim and that will make you happy then consider doing cd (perhaps a higher plan) so you have something to focus on and because you're doing something for you, this will make your hubby happy too. I know it sounds a bit mad and it doesn't have to be cd but just something hun.
Bit jumbled, sorry about that, but hope you understand. Thinking of you xxx