I've read a bit of your story and I see similarities and some differences. FWIW, my wife hasn't done a single thing about divorce. Hasn't even spoken the word. Closest she's come is to say she doesn't want to work on the relationship. Her actions say she's done, at least for the moment, and that's what matters. The most important thing (easier said than done) is to do the work on yourself without constantly worrying if it will make her notice and have a change of heart.
I had the exact same instincts as you, but I would say not to go to MC at this point. I did, and the counselor was anti-divorce but I'm not sure was the right fit for us. W went with me the first time, then insisted on going separately and basically treated her sessions as IC. The counselor broached with her having both of us come in again, and she pulled the plug. If the (potential) WAS is not invested, often they treat it as something they can cross off on a checklist. Tried that, didn't work, guess the marriage is doomed. It really takes two people willing to do the work.
My W also hasn’t spoken of D. Actually my real tangible evidence (other than her odd behavior) is fairly limited. Texting a friend about her unhappiness (with a weird comment about documenting something I said). A couple pictures in our cloud account that made it clear she was unhappy (I won’t get into details, it’s not important). The D book that I found, which it’s not clear she has even opened. Then I start with that evidence, and EVERYTHING seems like evidence pointing towards a D. Secretiveness. Lack of affection. Not sharing things with me. Telling me she “didn’t get a text”. She lied about moving a dentist appointment - did she go see a D lawyer for 30 minutes? Who knows? Who cares? I have prepared myself so I am confident if the BD comes... it’s not what I want, it is heart-breaking and April was the worst month of my life. I never thought I would feel so low. I was lucky to be on work travel where I could spend time by myself sorting things out, rather than being a hot emotional mess in front of my 3 kids.
I agree on MC. I posted on my separate thread that if we go back, I want to first speak individually with the MC (we did this before). I want to be clear that I am not interested in MC if my W’s goal is not to stay married.
The limbo feeling is the worst. I feel so certain that the BD is coming in June or July, and there’s nothing I can do. I can work on my behaviors here, which I will need to get through this difficult phase of my life. I feel like those changes are not going to prevent the BD in any way, and they are mostly about me preserving my sanity, and evolving into a happier, healthier person going forward in the next phase of my life. If by some miracle we can reunite and save this M, even better.