Another way to think about it is that she wants to run away from her current life. And you are such a huge and integral part of that. . Many people in this type of crisis abandon more than just the spouse, from what I see in RL and on here. Unhappy in this life, run to a happier life. Doesn't ever seem to work in the long term (wherever you go, there you are) but that's the impulse. She'll will discover you are not the problem sooner of later, but you can't convince her. Stay strong, you will come through this.