Shift your focus. It is time for you to get some support for you. I spent 17 years with a man that cheated and it wasn't until I started to heal my own childhood woundings that life started to improve.
You have no control over his behaviors and the more you focus on trying to control it you will move deeper and deeper into the abyss of repeating patterns. It is time to see what is in you that matches this painful picture.
I had believed all my life that other women were better than me. So, it is no mistake that I brought a man in that basically thought the same thing. It does not mean I "caused" him to cheat because the cause was in him before we ever met. It does mean that we matched and until I healed my own core beliefs nothing could change for me.
When we have painful, false core beliefs we will bring in whatever matches those beliefs. As we start to bring those beliefs to awareness and question them they begin to dissolve and our patterns will then release us.
Get support whether it is counseling, coaching, a group, books, seminars, etc. Gather lots of information on boundaries, self-care, co-dependency, questioning belief systems, etc. It is time for you to focus on you.
The more you distract yourself by focusing on him the more suffering you will feel. It is not possible to change him no matter how much you plead, nag, blame, cry, persuade, preach, or punish.
The advantage to focusing on you is it also leaves him to deal completely with his own choices. Right now, in some ways, you are actually taking on some of the energy of his choices and rescuing him from his consequences. This means he doesn't have all the energy in his space that he has to feel, see, and deal with every day.
Some resources I highly recommend are:
The Art of Extreme Self-Care by Cheryl Richardson
Boundaries: Where You End and I Begin by Anne Katherine
The Dark Side of the Light Chasers by Debbie Ford
Concious Loving by Gay and Kathlyn Hendricks