My situation is almost exactly like yours, with only a few different circumstance (for ex. I dont work and haven't since 1996 due to multiple physical health problems. Even if I *could* manage a full-time job, no one is going to hire a mid-50s person who hasn't worked in decades). But like you, I have no friends or family, no savings or income of any kind, no health insurance...nothing. I want out of my marriage SO badly and have for years but there just is no way I can do it and survive on my own. It is indeed, like you said, such a hopeless feeling and so I feel for you and my heart goes out to you. Sometimes I sit and marvel at how my life became THIS. I never imagined I'd feel so trapped and have absolutely no choice or power over my own life when I imagined my future 30 years ago.
Do you see a therapist or anything who could maybe advise or advocate for you in finding resources that would allow you to leave your marriage? I don't know if that's a dumb idea in general or not, as I told my psych doc and other med professionals I see about my situation and they were no help whatsoever in my case, but maybe for you they could be?
I hope you find a way to get out. No one deserves to be trapped and stuck in an abusive relationship or situation of any kind and it's not right that there isn't more help for you, or people like me. I am sending you lots of good energy and my inbox is always open if you need someone to talk to or just listen who understands and relates.