Even though you do need to be the rock for your children, don't forget about yourself. You do need to feel the emotions of this, so that you can step out of the "victim" role of this being done to you.
While it isn't what you want or what you have worked towards, it has happened and you have to move forward from here.
And while the timing may have sucked, Crazyville's perspective, I found interesting. Not necessarily just to your sitch. Just a way to look at any similar situation from a completly different perspective. Personally, I can see what she was saying and how it relates, and I can see your more relaxed side and how it relates. I have to admit, depending on the situation, I have a little bit of both of your thinking. Try reading it as a generalization instead of as directed at you, when you are ready and see if you can see what I mean.
BTW, your initial reaction from her, while the intensity of your anger may possibly have been a little misplaced, was the type of stuff I was looking for. No censorship. Just raw emotion. Sometimes we have to let it out.
"Acceptance doesn't mean resignation. It means understanding that something is what it is and there's got to be a way through it."--Michael J. Fox