How are intimate relations between you and your husband? Does he want it more than you do? You more than him? Has he turned to porn because of some emotional distance between you?
Porn is easy. You don’t have to deal with a real person. You just get instant access to your imagination and it is so much easier to jerk off. If you don’t want to or can’t deal with a real person, that’s a problem in a marriage.
Porn is just a symptom. You need to look for the underlying pathology. You may even need to take some responsibility for that. If you focus purely on the porn, you won’t get anywhere. I wouldn’t even talk about it. I’d suggest couples counseling if you can get him to go. Don’t use porn as the reason. What do you think is the real problem in your relationship?