Porn has a high relapse rate. The reason why is because the common approaches require a conscious decision to stop a habit and start a new one. The highly compulsive nature of porn and how it rewires the male brain makes the conscious effort nearly impossible. 

A reliable approach to stop porn is based in techniques used to help people with a phobia. Imagine being deathly afraid of snakes. If you were to stumble upon a snake, your immediate reaction would be to jump away in panic. You did not think about that reaction. You just reacted. 

It's the same way with porn. Once triggered or having an urge to view porn, the body reacts without thinking. Once triggered, it is very hard to control conscious behaviors. The solution is to condition the brain to think differently about the trigger or urge, putting you back in control and taking away the compulsive nature of pornography. 

Of course, this is just about breaking free from porn. In a marriage, the wife is emotionally harmed, and the marriage itself is damaged. All three issues must be addressed if the marriage is to survive and thrive.