It does sounds like your sexual behaviors may be signs of an addiction. Many people (especially those with histories of other addictions, like alcoholism) are prone to the "high" that can come from risky and/or taboo sexual situations. As you probably know from your recovery process with alcohol, the first step is acknowledging that your behaviors are causing problems, being honest with yourself and your wife about what is going on, and then seeking professional help both individually and probably also together as a couple. There is no easy way to start a conversation or open up about the issues that you've been hiding; there is no "good" time to do it. But the sooner you can be honest about the problems, the sooner you'll be able to get some help in changing your behaviors (which it DOES sound like you want to do).
Congratulations- you've taken a first step by opening up here and getting in touch with your own desire to change.