I am very sorry you are feeling this way
I have married with my husband for many, of years (17 years) and I know right where you are coming from when you say you feel this way. I have felt this way many of times due to our love making cutting way down. I mean WAY DOWN.
You, say you love your husband so very much and are so much in love with him. Then you, also need to trust him and if he tells you, the porn is not his, that someone sent them to him- maybe, you should listen to what he is saying.
Then again- males do lie about things
And they do play a lot of us for fools. Like, we do not know anything. I hate when males think that they can play us. Now, my husband and me we use to watch porn together. I am not going to say I liked it because heck no, I did not. I always thought to myself that he was picturing them doing those things to him- and also when we did do anything between or after the porn that it was their face he was seeing. But you, know my husband though he is not like that. My heart is the only one he holds. I was his first on everything and that right there it means the world to me. It means the world to me as well, because I know I mean so much to him and that he loves me and me only...
You, have though pretty much done everything
You, could have thought of trying with your husband. Now, all there really is left to do is to talk with him, let him know how you are feeling, what he is doing to your feelings and how much it is breaking your heart with him not being the same that he was when you married him... He could though always have something going on with him. Has he been put on any new meds? that might be also something that is going on. Has your husband been under any stress, has he been getting enough sleep, working to much? Does he drink? these could be the reasons he is having on his part
You, do not want to just jump and say
He is cheating on you, unless those questions turn out to be a "No" then you, can look at the reasoning that he meet be seeing another person on the side. Maybe though he did not really have true love for you, and thought that he did and say what a lot of people say "I am not in love with you anymore" or "I do not love you anymore" also they say "I love you, but I just am not in love with you" Well, I am sure you know this seeing you, yourself, said that you're so in love with your husband. Then you, would also know; that true love is something that is so very rare- so precious and it is just like something you would want to treasure for life as it was something you would want to lock up for life.
Now, I am more than sure you are feeling this
But can you really tell me though your husband feels the same way? does he really know what it feels like to REALLY be in love with someone and know how love truly feels? I do wish the best for you, and I hope you, find out the answers you are looking for. But you really are the only one who can say- what you, have not been doing right. You are the one who makes her own mind up on what you want to do about things. Listen to your heart- most likely it is telling you the truth...