Glad to hear your kids are doing OK w/ it. Not too surprised about D13 -- most teens in that age are so wrapped up in themselves, their circles of friends, and developing their own identity, that I think they'd be more worried about how/whether the logistical ramifications of the divorce will affect their social life. At least on the surface. Maybe underneath the surface, in the long run, it has more important psychological ramifications. My IC said as long as one parent is mature, stable and nurturing, kids will do OK. Obviously 2 such parents are better.
If possible, can you articulate a bit more about what your S10 was feeling? Did he resent you two? Did he blame himself? Was he angry about practical aspects of things, or ...?
My two kids are in approx similar age range as yours, and I fear a similar problem w/ ours....
BTW, I wonder if your W is having some type of a midlife crisis, and it's tied to some traumatic aspect of her growing years. And -- to state the obvious, maybe -- this is as much about a person's philosophy of life as it is about their day-to-day emotional equilibrium. If you don't know how to feel happy and fulfilled on a day-to-day basis by living in a stable, loving, supportive partnership, then you are going to get sick of your marriage at some point. I suspect your W has difficulty w/ that, and that has roots back in her whole life including childhood, not just your marriage. I know this is speculation -- but am curious what you think.
Me: 50, MLC/WW 45 Young kids Nov 2015: BD1 Apr 2016: BD2 Jan 2017: W filed Feb 2017: D final