I have to admit, I haven't read your whole sitch, but if he is intent on leaving, I would make up a list of how you see things working living separately - kids, finances, etc. I would do the work on what you need, so you are being pro-active and not reactive. You will find yourself in a much better position, and I think it helps level out the emotions that YOU are in control of your needs and not what he thinks you need.
