Update/Revision to my Emergency! 

I emailed her to ask her to come to the house to talk about this instead of handling it over the phone. She said she can;t tonight but would come over saturday. I feel relieved about that, although I dont know why. It's not like she said she would talk about saving our marriage, and in reality, Ihave no reason to believe she has or will changed her mind. But I at least have some days to prepare.
The scary thing is this, we've only been seperated one month, today exactly is one month. And she already has the papers? Everyone I speak to is surprised about this. Including myself.
Then I start thinking about the speed and finality of the whole situation and the way she has just become completly cold to me and I start wondering if she has met someone else. Everyone i speak to who knows her says she is not that type of person. And I truly believe she isn;t, but i also accept the fact I made her unhappy, and it's often unhappy people who have an affair. But I have a history of crazy thoughts spiraling out of control in my head, and under the circumstances, the time seems ripe for some serious mental projections. I kep pushing that thought out of my head, and I have asked her, both accusatory and civilly "have you met/are you seeing someone else?' She says no.
Either case, I have 3.5 days to prepare one last ditch effort to convince her to work on saving our marriage, but also build up some internal strength to face it and move on if the answer is still no.
Thank you everyone for your replies!