Welcome to a great forum. I just wanted to comment. I'm certain that my H was going through a midlife crisis last summer as well. I didn't realize it at the time but his mother had gone into A-Fib with her heart, and it took a month to straighten that out, which could have been the proponent that sparked things off.
But, my H also told me that he had known for many months that he was pretty much "checked out" of our marriage too, but didn't know how to approach me about it. After he dropped the bomb on me, he also let me know that he was feeling as if God was leading him down a different road away from me. He now tells me later that at that time, he was hoarding everything he could into his corner, to justify walking away from the marriage. My H was also involved in an EA with a co worker.
The thing is, it is amazing just how long the WAS knows inside how long they have been checked out... and how long they have known they are ready to leave, which is why it's a big shock when they finally let you in on what's on their mind.
I don't have much advice to offer, but I can say that the DB-ing techniques, the many people I have learned from on this forum, have been a huge help to my marriage and me.
