Have you ever considered a job with accomadation built in?
Not as far fetched as you might think, especially if you have a nursing background. Keyring are always looking for people to be sort of professional neighbours for vulnerable people living in the community.
Or you can live in an abandoned factory, office block to stop people nicking stuff. Again don't dismiss it out of hand.
Remember rent in London is the killer (followed by transport) if you can get it down....