It seems that the only way you know how to have any emotional connection is via sex. (Not an accusation, but what I gather about how you were raised).

Also, it sounds as if your wife is the one in control in your relationship (the dynamics and rules of anybody's relationship is not going to be exactly the same as someone else's, but I believe that we all base them on honesty).
Perhaps that is why you "cheated" (whatever the individual definition is). To gain some control.

Sounds like maybe your therapist will be able to help you sort out both of these issues.