Timing is a hard concept to guage. You've gone through the motions and are ready, but not really. And that's perfectly ok, because only you know when you are ready. And I do believe we reach a point where we know when we have had more than enough...often its over something minor that before we may have ignored. What sent me over the edge was more anger in what should have been a normal conversation about kids. It just sent me over the edge...he called me a passive-agressive manipulator (again) and it was THAT moment that the switch went on and my brain said "this is the time you've been waiting for". And that was that.
Having said all that - I now have to add that I find it so disturbing that she passed out while watching a toddler. Anything could have happened...it is a cringe-worthy moment. I hope you don't leave him alone with her like that again. Poor little guy.
Hang in there!
T