Flounder,
First like everyone, I am sorry we had to meet this way. In reading your wife's comments to you and her reaction to your deciding to file for D, it sounds very similar to what the AP in my infidelity story did.
Short version:
My WH had a workplace A with a married co-worker (she was married to another co-worker so my WH, the AP and the OBS all worked together). My WH was friends with the OBS prior to either of them meeting the future AP (she joined their work group years after my WH and the OBS had worked together) so as you can imagine the A was a colossal mess. I also knew the OBS, not well, be we had socialized prior to his marrying the AP. OBS and AP had been married about 2 years when the A started and had dated for about 2 years before they were married.
The A went on for about 4 months before I found out in 10/17 (dday1). I did not tell the OBS at that time and believed my WH when he said it was over. That was a lie. It went on for another year, before I caught him again in 10/18 (dday2). At that time I told the OBS and we talked a few times after. The A ended for a few months and then started again but I caught him after about 8 weeks in 3/19 (dday3) and blew it 100% up (people at his work found out, I told his best friend) and then post-COVID lock-down, I moved out spring of 2021.
After dday2 when I informed the OBS, apparently AP was telling the OBS a lot of the same things you said your WS has said to you: she was unhappy, felt like the "passion" was gone, didn't know what she wanted to do. When I blew it up at dday3, she was angry with me (ha - I could have cared less), blamed everyone else for her unhappiness, and continued her half-assed claims that she wanted to try to work things out even though the OBS was "closed off" and "didn't understand her" blah blah blah. Ultimately in 2021 the OBS said he was filing for divorce, which she did not contest, and she behaved much like your WS has upon learning of the filing. Their divorce was finalized in the summer of 2021 after they were married for roughly 6 years. Apparently the A was not her first inappropriate bit of behavior and OBS found out she had kissed some other co worker while they were engaged.
Needless to say my WH did not run off with her and she apparently is dating someone else at their work now and the OBS was initially sad to see his marriage end, but does not want it (or her) back and is moving on.
All this is to say your WS's behavior isn't really that unusual and it really isn't about you at all - it's about her. You will get though this and you will feel better!
You are the only person you are guaranteed to spend the rest of your life with. Act accordingly.
Constantly editing posts: usually due to sticky keys on my laptop or additional thoughts