I was married to a sex addict for 17 years. Even with counseling (individual and marraige) and group support he still did not change. In the end, I focused on my own healing and left the marraige.
Ephie nailed it. She really comprehensively described what addiction really looks like.
My recommendation is for you to heal you. None of us marry an addict without being a co-addict. We learn to enable, ignore, deny our own pain and wounding, minimize, take responsibility, drop boundaries, take the blame, blame, shame, stuff our own feelings, and give ourselves away. If you do not shift he will never have the chance. Or even if he shifts on his own you will find yourself struggling.
Find your own wounding. Read extensively on addiction, co-addiction, co-dependency, boundaries, etc. Find a really good counselor that will be straight with you, that will push you in a compassionate and tender way, that will support you in clearly seeing what is happening with you, and that has many tools to share with you that will support you in shifting your own behaviors, thoughts, and beliefs.
Addiction is a journey. I would also suggest that you look into all kinds of programs and especially ones that address the underlying issues not just the addictive behaviors. As Ephie described, addiction and co-addiction is about running away from the pain. The only way to heal is to face it head on. However, it is vital to fully resource yourself when you go there. You need all kinds of different support from a soft, cozy blanket to wrap in when you feel the feelings to a friend you can vent with to a gifted therapist.