Breakdown,
As far as the kids go, keep them safe, and answer all questions as kid friendly as possible (their shoes), when / if they ask. There's boatloads of resources to make D as kid friendly as possible (take that with a grain of salt as it is unfortunately what it is). Later on life, if they ask you could then share more of the truth, if desired.

My kids are similar in age to yours, so I know how difficult it is. I'm earlier on in my sich than yours, so I do use them as motivation to hang on right now.
Again, best of luck!