Hey, Andrew. In regard to your first message, yes, I felt exactly the same. In my case, I told my H I would be done if his EA turned into a PA. When I found out, I said it was over, and I meant it. But then he called me and said a D felt wrong and that we had something worth saving...So I stayed. I guess the PA wasn't my real bottom line, and you're finding that about yourself now. That's why I suggested before that you think about your real bottom lines. Maybe write them down.
The meeting with the L steers a lot of emotions. That's normal too. Since her behavior is so erratic now, I would definitely remove her name of the joint credit cards/joint accounts. My H and I haven't done that bc we never really had finances as an issue. He's been pretty transparent about everything he does, and me too. In terms of BDing, I think this also sends her the message that you get it: that she does not want to be your wife--at least now.
You will hear a lot of different things from family and friends. They all want to feel good themselves, and you/the kids suffering makes them feel bad, so the easy way for them to feel good again is suggesting you end your marriage. Typical behavior. They have the best of intentions, but they really don't know your sitch and the dynamics of your marriage. Only you and your W do. So if they start telling you stuff like that, try to change the subject.