Oops I just realized that I missed what you said about having a few weeks to get her to reconsider, while she puts her house on the market.
To that I say action (love) speaks much much louder than words. Unless you start taking massive steps to care for yourself and get a new oxygen mask in place that will relieve her of the burden, I don't see her changing her mind. Take the action to love yourself. Gaining the respect of others starts with our own self-respect and believing we are worth every effort to care for ourselves.
All the best to you right now. Perhaps sit down with yourself and remind yourself of all the times you've been brave in your life. Then make that call you need to make.