I'm very sorry to hear you had to do this, but I do understand. Three years ago I essentially made the same decision. We ultimately chose to back away from the abyss, after a couple of "stays," but sometimes it does come to this drastic step in order to protect yourself -- emotionally, legally, financially.
It's still not over, however. There is still hope for a reconciliation (I did!), and something like 20% of divorced couples later remarry, usually with better results.
I was given an exceptional piece of advice at this very same stage of my sitch, and I'm glad I followed it: treat your spouse with civility and grace, and it will pay you dividends down the road regardless of what the two of you decide to do.
