Despite I made many mistakes on dealing with our discussions about the issue what I will correct after going through this forum, one thing that got through my H when I found the OW love letter and his to her and he was mad at me was to say to him once and very seriously that all I wanted was for him to be happy because I was sure he was a great person.
May be this will sound silly or patronizing but you could go to him, look in his eyes and with your heart open say that. You might end up helping him more than you know.
At his point you and your girls must be the most important thing in your life however sometimes to go that extra mile to help someone heal becomes part of healing ourselves too.