I guess it was more serious than first thought. On your initial post I was prepared to write that this would all blow over.
It's funny, but once you are back together you forget why you fought so hard in the first place. Face it, marriage isn't all that wonderful. It's got its redeaming factors, but it also has bad things. I can see why you'd slip with DB efforts.
I think the proper way to go is not to suggest a solution at the moment. Your big opportunity is to hear her out, first and foremost, and actually consider what she has to say. If it's doom and gloom, so be it...be accepting that she feels that way. If it's a laundry list of your faults, own the ones that are true, and just acknowledge that you understand she feels that way about the rest. I don't think this is your opportunity to suggest a plan that clearly indicates that you want to keep her close to eventually change her mind.
But don't go all doom and gloom yet. She may fully intend to work on marriage with just a list of gripes. She hasn't said she wants out has she? Or has she?
Be strong Indy. You know you can survive this. Show her that you can. But also acknowledge that you know things have slipped and would like the chance to rectify the problems. But let her go first. You start by being the listener.
You cannot be lonely if you like the person you're alone with. Dr. Wayne Dyer