Yeppers, you are in full contact survival mode here. Actually, I am not saying the D is certain. I am saying the line is getting drawn and you need it to be the best solution possible for you and the kids. That should still be 'fair' in the opinion of anyone representing her legally or financially.
One day you will be glad you were fair. One day she should see that the plan was fair. It will never be what she wants. At this stage they want it all. They want you to feel the pain they are experiencing. You are not the sole source of her pain. She can't even put her own finger on that source. It will take months or years of suffering for her and those she brings into her life. She is in a transient stage of life she will one day look back on differently. Doesn't mean crap to you right now though, it is not your immediate concern.
You seem to have a solid grip on your view of assets and future plans. Don't let that get clouded, and your future will work itself out just fine. It may seem now like it will be different from what you always expected. But it will be ok.
Her's will certainly turn out different than she always expected. And it will be different than she is currently thinking. It will be sad. It seems so many of them are determined to be sad, and don't yet see that in their own mirror.