Hi Befuddled
I hope you're feeling stronger today. I've been disabled for quite a few years now. "Easy prey" is a good description. I also know isolation all too well - forced and chosen - both SUCK!
If I were you I wouldn't give your husband the satisfaction of killing yourself.
Your marriage may be dying, but your life is just beginning. You're in charge of your happiness now, so take some time to get to know yourself and what you want out of life.
You've been wounded, but remember you're not broken. I hope the right people and places come into your life to aid you in healing.