I don't really know what to say. I have been where you are at, or somewhere damn close and I just barely pulled myself back from doing what you did.
I cannot chastise you for it nor can I condone it. You did what you thought was right, something that has been feeling more and more right for some time now. The only think I can say I wish you had done differently, and more because it's reflective of who I think YOU are, is not have done this with such anger and angry words.
Trying to take someones religion away by casting judgment on them does NOT seem to be indicative of the man I have witnessed on this board all this time. You HAVE compassion and have shown it many times here. You have shown it to your W probably LONG after she deserved it but in all, I think you showed it because you truly ARE compassionate and loving in your heart.
Should you love this woman, this mother of your child? I don't know, but as someone else said, she IS going to be a part of your life for the foreseeable future and even if you do get a divorce, allowing that to be a constant source of pain and anger will do you no good.
I really hope you can get to a peaceful place in all this. If this is what it took to achieve that, then in the end, maybe it's what's best for everyone. Please, take care of yourself and realize that you don't need this anger to get through this, you only need your strength and your God.