It reminded me of a much smaller experience many moms have had. One of the kids is injured. Mom does all the right things: pressure on the bleeding cut, ice-pack to reduce swelling, getting the kid to ER, telling the story repeatedly to nurses and doctors, comforting the frightened child, going home with the instructions to watch for signs of infection. Mom does what needs doing. She holds up. She manages to do what needs to be done for those who depend on her.
And then, the next day, she accidentally breaks a glass, or one of the kids spills a quart of milk, and Mom loses it. She falls to pieces. Somebody tries to comfort her that it's just a little accident, that it's easily mended, that it's gonna be okay. And that only makes it worse, because she knows it just a little accident and that she shouldn't be crying or losing her temper or whatever. But it's not the broken glass or spilled milk, it's the incident of the previous day that's getting to her.
I suppose it's good to be able to hold up during the crisis, even if a person falls apart later. But it's pretty unexplainable when it appears that such little difficulties can take somebody down when they've managed to make it through so many bigger problems.