Heather

I dont see the problem between you and H as the porn. I see lying as the problem.

you are finally ready to start setting some boundaries with your H. Thats good.
The thing is ususally by the time a woman is ready to start setting boundaries, the way that she implements them is .... unfeminine. I watched 3 women do it here, and a lot more IRL. When her boundaries are acknowledged, her respect is allready gone, and next goes her attraction, because of how she implemented them.
I agree with gottman, (and cobra) that the Wife needs to be able to affect her H. She has to have enough relevance to him, so that she can see he cares for her.

The way your H is, if you set boundaries with ultimatums, you two will ram together. There is no yin/yang in that. It can only lead to shattered defeat. If you want to have your H care for you, your going to have to implement boundaries, with vulnerability. Instead of appearing strong (anger,demands) on the outside, and nursing the wounded bunny inside, (incongruent) your going to have to show the bunny, and be strong on the inside (not letting someone else change who/how you want to be).

Youve become too much like him Heather. You have to dig deep and be who you are.
You cannot TELL him what to do. You wouldnt want to even if you could.

I dont know if your H has an addictive personality or not. It very well may be that he does. Thats part of why I said earlier to you about 'we can only accept and make our choices based on that acceptance.'
Your H is very masculine though. He needs feminine energy to balance him out. That often comes in the form of porn, alcohol, etc. I do not have an addictive personality, (purely thanks to my parents/genetics), but there was a time when my alcohol consumption (not to mention other feminine energies)comparitively made your H's alcohol consumption amounts look like a glass of wine.
Remember, Thats not one of the reasons why x left. It stopped long before. (I say the latter to preempt questions) She left because I froze her out emotionally, and I did that because I wanted a)acceptance, b) her to make a choice. I made every other one, I *shouldnt* have to make ME one them.