That's the thing. Just because you are forbidden by your wife or feel guilty for having these feelings for her, it doesn't mean it can and won't stop. I think the reason you are emotionally cheating on your wife is that you aren't happy with things at home. Be it too boring, your feelings for her faded, etc. etc. If you really care about your wife and your marriage, you might want to look into it. That can be the only feasible explanation I can think of for your situation.
I praise that you were honest and told your wife, although if you were able to squelch this on your own you could have avoided some animosity. It brought to light some problems in your marriage to her and alerted her that this needs help to. The sooner you dive in and fix it the better.
What problems can you name off the top of your head with your marraige?
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.