Broken, you've received a lot of good advice. I want to add that you may want to seek outa a good Christian therapist and, if you haven't, join a men's bible study. Also, make sure you stay in the bible and continue to strengthen your R with God.
I would like to give you some advice that helps me: 1. Put God above all else, including your W and kids. Only then , can you be more like the man God intends you to be and to better handle this situation. 2. Forgive yourself, your wife and your MIL, even if your W and your MIL are not seeking it. You need to forgive them more for yourself than they need it. 3. DO NOT WORRY WHAT OTHERS THINK. I use to worry about what others would think if they knew what happened and what my W is doing. You are focusing on the wrong thing. Trust God. With EVERYTHING. 4. Put on the armor of God everyday (Ephesians 6:10-18). 5. Ask yourself if you feel God is telling you to stand. Pray to Him, asking that He guide you in every way. 6. Don't treat your W as if you are better, more pious, or superior to her. Don't be a martyr. Love her as God instructs. (1 Corinthians 13) 7. Know this is a spiritual battle that you have no power but God does. Satan ids like a prowling lion looking for someone to devour. (I can get the scripture later since I'm writing this on my phone). 8. It is very easy to fall into the trap of the world's ways and to accept the same lies that people we love have fallen prey. We are not better than our spouses and can quickly succumb to the same traps. Again, the devil is a liar and would love to destroy you, your wife, your marriage, your children and your family as a whole. He cares nothing for you but what he can do to hurt God. 9. Trust God
Me:56, W:51 D:26,S:24,S:22 Married:18 Bomb 9/27/06 Separated 11/27/06 Divorced 10/6/08 Leaving it up to God