I fully understand about venting b/c I'm that way myself. Maybe if you had another person you could vent to (face to face) it would help releave some steam and you could reframe from going off on W.
You wondered if she left some things purposly for you to find. IDK, but when I was in the middle of my EA, I did some very stupid things b/c my brain was fogged out. I mean, it was like it never occured to me that another member of my family could be on my computer...and OM thinking it was me...would pop on and say something. I was told that I even left an email open while I went off doing something else.
So, I think your W was stupid and crazy, more than her "planting" evidence for you to find.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!