I knew somebody to whom this sort of arrangement cost $$$.

The woman would not move out; he had to move in with his parents and give her a formal vacate the premises note; she did not vacate the premises but instead called the police alleging domestic abuse. He won both cases (the civil case to evict her and the criminal case), but it was an emotional roller coaster for him for many months and cost him thousands of dollars.

So it is time to stop feeling stupid, sad, and depressed, and start thinking about how you would avoid a mess. Maybe you need a written agreement with her. The situation calls for legal advice more so than for T advice.