You are married and any feeling that you have for another woman that is not your W is wrong.
Here is what God has to say about your sitch. Proverb 5:18-23 18 May your fountain be blessed, and may you rejoice in the wife of your youth. 19 A loving doe, a graceful deer— may her breasts satisfy you always, may you ever be captivated by her love. 20 Why be captivated, my son, by an adulteress? Why embrace the bosom of another man's wife? 21 For a man's ways are in full view of the LORD, and he examines all his paths. 22 The evil deeds of a wicked man ensnare him; the cords of his sin hold him fast. 23 He will die for lack of discipline, led astray by his own great folly.
I know that you came to this site for help, not to be judged and condemned. All of us here want to save our M and support each other in doing so... So with that said you need to come clean with your W and deal with the reprecusions of your past mistakes. It will be painful for both you and your W but since your feelings for the OW have not been dealt with I feel this is the only way for your current M to stand a chance. I agree with walkingback go to counseling - it will help. You have a long road ahead of you and if you want to save your M(I hope you do) this is a good forum for support. Otherwise, you just walked into a pack of hungry lions that have no simpathy for you. Sorry just being honest.