When I first discovered the EA, I blew it up immediately. Couldn't control myself. Also, that day I started working on my addiction.
When I discovered my wife still in the EA, about a month and a half later, after saying she was done, it was different. I was calmer, and after reading DR, and practicing detachment and validation, expressed that I knew everything (which I did - spying on her phone), and that I wouldn't live in an open marriage, and that whatever she was planning, that I hope she was happy, and that I'd be fine.
That put her on a spin that ended up with us both committing to reconcile in the last 48 hours. After she filed the D, but I haven't been served. WOW.
I'm giving you the advice that I think you already know - get your feet underneath you, and get to the point where you can rationally, calmly tell her the same thing I told my wife, and be able to walk away. If she's as cold as you say she is, she'll either continue to be as cold as ice, or your statement will snap her out of it.
Anger at her, and yelling, or any confrontation will just reinforce that her coldness was the right technique that she began months ago to cope with the stress of what she was doing.
M46, EXWW46 M15 T17 D20, S19, D13 M - Addiction since 1998 W EA/PA #1 2013/2014 W EA #2 June 2015... BD 1 Big D talk 9/15 BD 2 - EA/PA disc 10/30/15 Served D 1/22/16 Divorced 5/25/16 (yes, that fast!)