People with far more expertise than I can probably help you.
The first thing I think is that you shouldn't help him with the divorce process. If he wants one make HIM to the work. Don't help. Make it clear that this isn't what you want and then step back. Many times, they don't have the energy it takes to contact attorney's, fill out paperwork, etc. That doesn't mean he won't though, just don't help it along.
Try not to have any expectations either way.
Sorry you are at this crossroads. I know how hard it is to have a sick mom in the middle of all this mess. I was there too a few years back.
