I read your story and it is somewhat similar to mine. Now that I think about it, I think my W may be having an MLC as well. She's a year younger than yours and her older sister went through it (and was on the verge of divorce) around the same age as well.
My W also recently started a night job and our time together has been limited as well.
And also some of the things she has said since her first BD; "I can't go on like this for another 40 years." "There has to be more to life than this."
And so forth.
I am still DB'ing (or trying to) and I'm hoping we can get through this.