It sounds like you have already made up your mind, so there isn't anything anyone can say to you now that will change the course of events. Once the bond of trust and fidelity has broken, it's very hard to establish it once again. Since your desires are far from your wife, it's a losing proposition. All we can ask you is to be fair and consider your wife, there is no way that she coudl come out of this unscathed. If you must leave, then do it, but be as considerate as possible, not injusring her any further by prolonging a false marriage.