Having been there, I thought I’d give some of my perspective, though, with acknowledgment that every situation is different.
Despite the fact I came away with 2 incredibly awesome kids, my marriage was a train wreck from day 1. I didn’t realize how bad it was until I was out of it for 6 months. I discovered (in time) and after the marriage, that it wasn’t so much her that I didn’t want to lose, or felt love toward, it was the idea of her. The idea of the Great American marriage. Of course when you are in the heat of it, as you are now, its very hard, if not impossible to see that.
Advice? From what you describe it sounds to me that she has left you already. She is probably staying out of fear of divorce. I was blind sided by my divorce while living much as you are now. I fought to save it, to no avail. In the end however, once we got through the pain of separation, I am happier now than I have been, maybe ever. Yes, I am missing someone to share that with, beyond what you can share with your kids, but thats okay.
My point? You don’t have to give up, but you should back off. Leave her be, pursue your own interests, let her know you want to save it, but don’t throw it in her face. Go out. Make some new friends. Join a sport or something. You might want to gently suggest therapy. Tell her its worth saving and when she is ready, you are. But don’t force the issue. If she goes into it with her claws out its only going to reinforce her negative feelings toward the relationship. You have to give her big time space, and you HAVE to start preparing yourself emotionally for a separation. Don’t get taken off guard and don’t try to go to war with her. You are going to have to embrace the cheesy and frustrating philosophy – If you love something, set it free, if it returns, it was meant to be.
You don’t want to hear this, but you might consider researching divorce just to have the knowledge. If she is as distant as she sounds, don’t be surprised when she blindsides you. Be prepared. If it happens, you will maintain your sanity best, if you keep a level head, and try to work things out between you and not between lawyers. But have one lined up that is trust worthy. You’ll know a trust worthy lawyer when you are told, “You don’t want to have a judge decide these issues for you. Work it out.”
Best of Luck to you and don’t despair. You’ll find peace and happiness one way or another. It just might be disguised as something you never imagined would bring it.

