I've had a glimpse into the very dark underbelly of what this situation can do and how it can hurt. I honestly feel as if my ex has no emotional capability beyond connecting with someone on a very superficial level because of this. Hence, from some things I've seen over time, I do believe he may be using drugs to avoid the pain even further.
That said, Rache... we in this society often take a very Puritan-like attitude towards sex and nudity and then we do a double-take through avenues like MTV and HBO. We're very much polarized on these issues, and if your H was raised in a strict household, there could be guilt issues stemming from looking at porn too. I'm not sure what the "right" attitude to take is re porn. It did play a role in the destruction of my M, but I do think it was merely a symptom of another problem... the need for an escape or a fantasy during a midlife crisis.
Your H is connecting with you by being honest about the situation. Yes, we can become addicted to this stuff and this stuff can be very harmful. However, it's all in the attitude we take in how it affects our lives. SOS makes a good point in that it is expending his energy away from you.
Is there a way you can make him feel more comfortable and open up about this issue? His feeling bad about not having had more women while in his youth is bs... he's talking lust, you're talking love. Need to combine a little bit more of those two to make a good R really work well.
Only you know what's best for you in your own heart. But realize too that if you really want your M to work out, there seems to be a lot of opportunity!! My heart goes out to you... I have a daughter your age