The first thing I would say to someone who has just learned about her partner's addiction to porn/sex is to find support for themselves whether it's a counsellor face-to-face, a telephone helpline or an online community. One thing you have to realise is that the one with the addiction can't support you and help you through it because they are not going to have what it takes to understand your trauma. In fact, having their behavior dragged into the open is probably traumatic for him. It's also important to stress that your recovery and his recovery are going to follow different paths and you will both be wildly out of sync. For him it's the end of something they want to leave in the past. For us, d day is just the beginning a long and painful process. Also, the RELATIONSHIP itself needs to recover and this is something quite distinct from YOUR recovery and HIS recovery.
Secondly, wise up about porn addiction. There are some excellent articles on yourbrainonporn.com. It's important to understand that porn hijacks the brain's reward system and burns pathways into the brain which leads to the development of the addiction. When guys say "it's not personal" or any reflection on their partner, that's what they mean. There are some excellent books. Sex Addiction: The Partners Perspective by Paula Hall was the one I found the most helpful. There are others: Love You, Hate Porn is a good one, The Porn Trap, Always Turned On and In The Shadows of the Net are others. I don't get along with 12 step-based "Anonymous" ideas but some people find them to be lifelines. It might take some trial and error to find a resource like a book or a program that can give you structure to your own recovery.
Thirdly, accept that your emotions are going to be all over the place for as long as the next six months . When people say it's a mad rollercoaster ride, believe me, they are not kidding! Chances are it's going to take months to find out the true extent of your partner's acting out, and chances are he's going to be the least reliable source of information. You WILL be lied to and it WILL hurt. Just when you have come to terms with what you know already, chances are something else will come to light. Your partner won't look so good to you any more, now that you see him as a porn addicted manipulative liar. You'll be angry at him for what he did. He'll be angry at you for exposing his secret world. In between these traumatic episodes you may well be trying to reconnect emotionally and sexually. This new situation will be crazy-making. HE will be crazy-making. That's why it's important to get support for yourself and get wise to this weird thing called porn addiction.
A few more things. Don't forget to take care of yourself. Chances are you were neglecting your own self care and putting yourself last. That has to change. Get to know yourself. We read a lot about boundaries and values in the self help books and these were just abstract concepts to me. I realised I never properly had the opportunity to develop my own views on many issues. I thought I had my own outlook on life but I was certainly not up to date when it came how the pornography industry operates today. I have had to "update" my views on human rights, specifically the rights of women and girls in the context of the global porn industry and the sex trade. This has been helpful for me, and gaining a wider perspective has helped me in my recovery. These are my values.
Too often a woman whose relationship has been blighted by porn is criticised for not liking sex, or being too unattractive, or even assumed to have outmoded morals or religious views, etc. There have even been men coming on here are trying to provoke us on these fallacious grounds. So it's important for me to be able to say WHY I do not see porn as having any place within my relationship and in my life. Sex ? it's possible to have an exciting, multi orgasmic, mutually satisfying and loving sexual relationship with porn, or overpriced lumps of buzzing plastic for that matter. I've managed to have a great sex life without any additional manufactured crap so I don't see the purpose of it. Attractiveness ? we can't all be 21 and youthfully beautiful forever, but neither can the men in our lives. That said, there are many ways of being beautiful outside the narrow definition on the pornstar "ideal". Besides, what's so great about some ghoulish sex cartoon? Is that what we are expected to impersonate to be considered "sexy"? Are you kidding?! Religion/morality ? I live in a secular society where there are people of many faiths and no faith at all. If I have a moral view it's the dehumanising ugliness of porn and the sex trade, the right to buy, rent, use and discard human beings for the sake of a fleeting selfish "pleasure" that I find abhorrent. I say all of this because recovery also means learning to defend myself against porn-sick idiots.
I hope this helps add to the wonderful advice given here.