My ex husband is a sex addict. He was never as far along as you though, as he would not actually admit to it. However given the long list of behaviors, I know this to be true, and I have sought help for my recovery accordingly. I did end up catching him in bed with another woman, which is how our relationship ended. However his personal MO throughout our relationship was not physical affairs, it was compulsive masturbation and porn use, especially masturbation with the theft and use of my underwear, so I think I can speak to this a bit.
The fact that you are even willing to admit that your use of pornography is infidelity is a big step in the right direction. I truly hope that you believe that, and you are not just here to placate your wife. I applaud your honesty regarding the behaviors you engaged in. I imagine that brutal honesty is a byproduct of your 12 step work. It is good to hear that you are working the steps, but along with secondtime, I would like to hear how long it has been since your last relapse, and how long your longest stretch of sobriety has been.
Please, please, please start listening to the podcast, Helping Couples Heal. It is produced by 2 CSATs, 1 male and 1 female, who go into all of the facets of betrayal trauma and sex addiction. Start from the beginning, as it does progress forward. If I were you, I would listen to all of the podcast episodes they have available, all the way through. Take notes.
Something they speak about which will be highly useful to you is their use of the partner trauma model rather than the codependency model. It is essentially the acknowledgment of the partner (your wife) and the trauma they have endured, right from the get go, rather than pathologizing her behavior as codependent.
Also, as sex addiction is a shame-based affliction, please look into toxic shame. Devour any and all resources you can find on that particular topic. I think you will find quite a lot about that topic is relevant to you. Same with intimacy avoidance.
If you want to do something, make sure your wife is working on her recovery. Make sure she is putting herself first and doing the work to heal herself. Make sure she has time for her hobbies and gets a mental break from all of this.
If you want to do something for her, I would suggest sharing the podcast with her. And as secondtime wrote above, taking on some responsibilities for her so that she can have a much needed break.
Are both of you seeing your own individual counselors (ICs)? If not, this should be next on the list.