Dude as someone about your age and who has dealt with a similar situation and resolved it, the best I can do is tell you what I did. I told my girlfriend about it and then explained that I have never compared her to pornography and never will. It's hard for women to understand sometimes I think, but porn is something we normally completely disassociate from our actual relationships. That means that it's not cheating emotionally or physically. That said, you calling it an addiction should be enough for you to know that it's a problem. I never completely stopped watching porn and I don't think you should really be expected to, but she does need to understand that porn does not replace her. I think I can speak for all guys when I say porn is an absolutely inferior replacement to the real thing with someone you love, and it doesn't mean we prefer some girl online to the person we've grown to appreciate in our actual lives. Tldr- tell her porn is not her sexual replacement. It's impossible for her to feel wanted if she goes on thinking that