Sounds like my idea that she might try to pass any blame onto you was correct. I think you would both be better if you were out of it
Here are a couple of suggestions
You say you are in a tied house. Start looking & costing for rented accommodation; private, housing associations, and council. If you arrange a meeting with an association and explain your situation and the pressure, you might get a priority. Get your name down, you can always decline an offer with no problems, as they will always have others on a waiting list
You can usually get a private rent quickly, and just because you're in it doesn't mean you have to stay forever
Do you know anyone with a spare room, shed, garage or similar you could use for a while? Start to move your furniture & belongings into it so that when you do leave you will have less stuff and can make your move fairly quickly. I can anticipate all sorts of ructions, fun & games and unpleasantness when it actually happens
Have a serious look at your finances, income, expenditure and so on. You might find that you could manage on less money, at least for a short while, so that you could afford for your wife to leave, even if she hasn't yet got a job. Get professional advice and see what help is available. Where I live Lancashire County Council produce a booklet on financial advice & assistance for over 60s. There may be something similar in your area.
A friend lives in a rural area, Cumbria, and is a self employed cleaner; never seems to be a shortage of work - various houses, a pub, and she's just started doing a local school.
I was a chef/cook in a nursing home, and I know that schools, nursing homes, hospitals and so on are often looking for kitchen assistants
Can't be any worse than her present situation