What happens in porn is it's like a drug. You start out smoking pot, lets say. But over time you need to smoke more to get the same effect. Eventually you need a stronger (more dangerous) drug. And it continues to escalate.
Porn has the same effect. You watch porn. But eventually the stuff you watch gets boring so you need to find porn that pushes it farther, getting into more fetish base ideas. The longer you watch the more you need to get into stranger acts to maintain the arousal. Or even just curiosity. You stumble across something and it may strike you as curious, so you investigate and get into it.
Also consider porn is a huge support of sex trafficking women and children all over the world.
Lastly, it's not your husband turning you on. You're getting aroused by other people (much as you want to deny it, it's true). You wouldn't be getting turned on if you weren't watching porn. Just because your focus goes to your husband when you get turned on doesn't change the fact that it's the porn itself getting you excited.
And eventually you'll find yourself wanting to watch it when he's not around. And that will lead to you doing other things when he's not around. And before you say you never would, don't lie to yourself. This is what porn leads to, this is what its all about.
Another thing is the porn industry is all about degrading women. While the females in the movies are called 'stars' in reality, behind the scenes they are treated quite poorly. Mostly porn is about a man getting what he wants from the woman, regardless of if she's getting anything from it herself. Women are just things to be used to satisfy men and should be grateful that the man wants to use her.
I heard recently that the new trend in porn is violence against women. While this has always had a side fetish in porn (bdsm, which could be aimed at men or women) the new 'norm' is mistreating and degrading women in mainstream (not just fetish) porn.
Not to mention porn ruins countless marriages all the time. Is aimed purely at lust and selfishness. So the effects of feeding your spirit with lust and selfishness and whatever other things you wander into as you delve deeper into it, plus, eventually, the addiction that Will form. I mean, you said yourself your husband is addicted. Meaning he is not able to be in control of his mind and body, but rather lust and selfishness are controlling him. Which means Gods spirit is being pushed aside. Any time there is addiction that means something other than ourselves or God is in control of us. We are not in control. Does this sound healthy mentally, physically or spiritually?
And the guilt that follows that seems to never let up.
Well, consider the above statements and decide for yourself if this is good.