Adapted from a recent online discussion:
How do I go about ending an "emotional affair"? I don't even know whether the other person involved would classify it as such, but I know my husband would, so I feel I should get out. However, the guy is a longtime friend and has done nothing wrong, so I feel strange about a formal "breakup."
Pull away. Reveal less. Invest more in your husband, consciously. You can do these to nudge yourself toward balance. If it turns out you can't get balance by increments, then you're going to need to say something along the lines of, "I'm coming to believe the amount of my time and myself that I share with you is unfair to my husband."
For Question Mark:
For what it's worth, it is very likely your husband knows you have a relationship that detracts from your marriage. Unrequited love/like has a way of creating a loneliness that others pick up on but may not be able to qualify. In addition to trying to pull back from the person who is your current distraction, try being honest with your husband by saying something like, "I know I've been distant, and I really want to try to reconnect."
I think you will find it easier to put this "emotional affair" behind you if you have a real purpose in front of you: rebuilding your marriage with help from the necessary parties.