I am sorry to hear of your situation. It is very concerning to hear about folks throwing away loving relationships, families, homes, and especially when there is children involved. I go back to this study I read a few years back as to why women cheat. The Articles gives ten reasons why women do this, I hope that you can use these to possibly look within yourself to see if maybe you can see these being live and real in your relationship and hopefully at the least, be able to discuss these with her in hopes of getting beyond this and back to the love that you obviously have had or it would have not made it this far. The reasons are: not enough sex, women wishing to sew their wild oats, self esteem, revenge, lack of intimacy, feelings of being neglected, emotional withdrawal, bedroom boredom, an exit strategy, and tit for tat if you've done the same.
Seeing the obvious that many of these can be lumped together to ideally foresee that the reason for her cheating has a lot to do with her sexual self and her view of how she thinks of herself or even how you should be treating her. the attention the person she cheated with probably outweighs the attention possibly you give her in daily interactions and then in bed. Try to not get defensive with her and look at your inner self to determine if truly you can relate to incidents where you have not provided a nurturing side to these parts of all human relations whether sexual or none-sexual. i hope this helps someway and to know that there are those of us who will be thinking about you. So hang in there and give some thought to NEW and innovative things to do for at this point it does not sound like you have anything to loose but, a lot to gain. The compliance Doctor