running away from your problems is the quickest way to come face to face with them.
Man up.
Yes these times suck, the pressure can be overwhelming, coupled with having to function while working, taking care of kids, home & yourself. It's lot on your shoulders.
But you can handle it.
Don't up and go on a trip and leave everyone behind (not yet anyways).
Do the required work, invest in personal development, feel stressed out, grab the mp3 player, go for a walk, go to the gym, sit on a bike, run around the track, pump some iron, hang out with friends, talk to a good friend and let out your frustration (ask their permission first).
It may get worse (probably will) before it starts to get better.
Don't obsess about the facebook thing, let her be who she wants to be as long as isn't doing it while using you as a doormat and emotional healing tool.
Setup a schedule with the kids & her so that you don't have to do as much contacting, focus on yourself and being a great dad - that's the part you have control over, that's the part you work on, that's the part that will fill up your time.