The Freedom Begins Here website has a free download that may be of help to you. It is Deb Laaser talking about her struggle when she found out what her husband was involved in. It is available on the home page and this is the link: http://www.freedombeginshere.org/videos/a-spouses-perspective
It is called "A Spouse's Perspective."

I'm so sorry to hear of your pain. As the wife of a sex-addict that God has set free, I know how devastating the sin of another person can be. I'm sure your husband already knows that being unfaithful begins in the mind. If that were not true, Christ would have never said that if you "look" at a woman with lust in your heart, you have ALREADY committed adultry. Unfortunately, you can't force a person to change or to get help. The only thing you can do is protect yourself. Someone once told me, you can't control another persons actions, you can only control what you are willing to accept. I will be praying that God gives you the wisdom to know what to do and that through Him you will have the strength you need. My marriage is a living testamony of the power of the Cross and God's healing power!