Thank you for your heartfelt letter. There are several factors to highlight. First, the unavailability of this person — I believe — is part of the attraction. This is almost always the case. The impossibility of it sets up a dynamic where you can want — and not have. The fact this is an unrequited love means that you have chosen not only somebody who is unavailable by circumstance — but someone unavailable by his decision. This is important. Did not overlook this. Craving him, the quest, the desire itself, along with the infatuation and unavailability, may be all part of this package. The real issue is whether or not you want to remain married.
The weakness in the marriage is the important issue. Find out what’s not working there, and explore. All of your efforts need to be on deciding whether or not your marriage has enough to be sustained. The other person is typically a symptom of the weakness. Attending to your relationship with your wife — and deciding if that is worth keeping—is the first and foremost work to be done. A good couples’ counselor can help. The find help tab at the top of this page may be able to help you locate someone in your area.