Sounds very much like my story, i look after the finance, but i also work and earn a reasonable amount. He doesnt have access to most of our money, which is great as his spending is ridiculous.
Things are happening fast for you and for now this is over, ok and please try to accept that he wont snap out of it overnight and that yes you can easily get to D. I know its rubbish, im just further along in this and please believe me that i have done all the tracking and so on. Its devastating when it happens.
Call upon your family, gal as much as you can, spend time with the kids, yes they will be confused, its so important that they have a consistent sane adult in their lives and that is you!
Take care of you, have a bath, watch a movie. Act as if you are moving on and happy. Fake it until you make it!