Hi, it depends, I'm guessing (and I'm not a lawyer) on the law that applies where you live. I think it would be worth a chat with a lawyer though (even as a one-off). If you were coerced into signing over the house to him and can prove you lacked 'capacity' at the time of signing due to mental ill health, you might be onto something. You might also want to ask the lawyer about the fact that he did not truthfully share/disclose information with you about the house being solely in his name. Did he defraud you in some way? It's worth asking the lawyer the question maybe?

It is odd, and no doubt very stressful for you, that you're living with him still. Surely you received 'some' settlement from the divorce? If not, definitely tell your lawyer as I don't think that would be an equitable/fair outcome - depending on the circumstances/case of course, which I have no knowledge of.