I can relate.
I'm married almost 49 years, and I know that if my wife had ever
left me, I would have been "destroyed".
Very sorry to hear about your problems - of course, it will all work
out for the better, eventually, but that's a LONG time from now.
As Stuck mentioned, Very Important to remain a large part of your
childrens' life. They really NEED YOU, terribly. They are more
destroyed than you are - only YOU can keep them together. And,
you will never see, or hear, from your kids how much they need
you - they might even think they hate you for the divorce - but,
they don't. They do Love You, and Need you Very Much
Good luck with the long journey ahead.