Welcome to the forum. This is a great place to vent and get ideas and support for your situation. Your situation doesn't sound entirely different from the way mine was a couple years ago.
Have you read the books Divorce Busting or Divorce Remedy? DR is the newer of the two and is considered slightly superior. Those books will describe where your wife is and how she got there. From what you describe, I don't think MC is going to help, and will likely just push your W farther away. Get DR, read it, and start implementing the strategies there. Also, read up on some of the longer term situations here to get a feel for how these things go. Each situation is unique, but it's amazing how many similarities there are as well. I think there is a pretty big difference between the walk away husbands and the walk away wives, so I'd concentrate on the WAW stories.
There is a poster here named sandi2. She often posts a big list of don't for husbands in your situation. If you search for her postings, you should be able to find the list. Read it and live it.
You're at the beginning of a long journey. Don't think anything is going to happen quickly. Just resign yourself to the fact that this is going to take a long time or you will be continually frustrated. There is a saying "Don't believe anything they say and only half of what they do." I have lived this myself for going on two years now and that saying is dead on right, but it may take a year before you see it yourself.