I would prepare for her to try to preempt what she probably believes is your imminent filing on HER, by filing on YOU.
I would separate my finances immediately.
I would prepare for her to possibly try to position your moving back into the marital bed as "emotional abuse"; read up on it, and talk to your atty about any vulnerabilities you might have in this regard, as well as any other do's and don't's at this point. BE VERY AWARE OF ANY ATTEMPTS BY HER TO PICK A FIGHT WITH YOU. Do not respond if she does, other than the usual "I'm really sorry you feel that way."
Others may have other thoughts; those are off the top of my head.
