As someone who just exited her 20s I can tell you that I would not want to be right backing to acting like I was in my 20s…especially if I was already in my 40s. That is NOT a good look for anyone. Her life is not shiny, it is not sexy and fun, it is denial of the worst kind. Give yourself a pat on the back for being able to see YOUR life exactly as it is…your wife is going off the rails right now. Alcohol might be out of the picture for her but it sure sounds like she's trying to find the next rush with any implosive thought that comes her way. That is no way to live.
I don't have the experience that you're looking for or answers to your questions. This stuff sucks but it does eventually get better. Hang in there and keep taking care of yourself and your kids. You're setting a good example for them right now.