Long Term Relationship and NoFap

so, I've been dating an incredible woman for a little over a year now, and it has been one helluva ride. For one, she was my first sexual partner. For two, she ended up going to prison for a bit (she's in a halfway house now, hers were drug related-charges, we're both sober now), and for three, there was a pregnancy scare. Generally, our sex life was pretty good, but there were certainly times I couldn't "perform." Hell, there were even times I'd go to the bathroom to masturbate while she was in the next room over. Typically, I lied to her about it. In the months she was incarcerated, I used porn pretty heavily. The most recent time we attempted to get it on I couldn't get hard. I attempted to abstain from porn after that, and I lasted about two days. I look at all the symptoms of porn addiction, and they fit me to a T. Additionally, I have become clean and sober, and I'm trying to find something to fill the void. I want to do right by her, and I want to get out of this habit. My question is, has anyone had any luck with 12 step groups? They've kept me sober for almost a year now, and I'm wondering if that's a good route to go for my porn addiction. She's been bery good to me, and i owe it to both of us to stop this.