Just know that you're not the only one dealing with this. My situation is nearly identical - 4 kids, 12 years of marriage, wonderful life, haunted by my wife's past with 2 previous partners. My wife is amazing and nobody would ever guess that I struggle with this so badly, but as so many people have mentioned...you need to get help. I know I've forgiven my wife, she's been forgiven, heck...I've even forgiven the other guys. That doesn't ever take the dagger out of your heart when certain things are mentioned in church, television, or life in general, and that's where you need help. I made the mistake of trying to work this out on my own for years. It caused me to struggle with my testimony, and yes, even suicidal thoughts. These thoughts eventually become obsessive and that's where professional help and possible medication are needed. It can put your mind in the right place to allow the Spirit to do its work and let the Atonement heal you too. Again, it's easier said than done - I still struggle from time to time. What's all the more difficult are the answers from people that don't understand where you're coming from. In the church, especially, you're taught to abstain from sexual intimacy before marriage - period. What happens when you do just that but reap the repurcussions of your beloved spouse's poor decisions? That's where I struggled. I ended up with an STD about 5 months after we were married (it takes that long to show up) and it was obvious what was going on because I'd never broken the Law of Chastity. It broke my heart and still does. I have physical scars to combine with mental, emotional, and spritual. Get professional help - it'll be OK. If she's stuck it out (like my wife) while you've struggled so badly, then she loves you and will help you through this.