1. Take care of yourself -- surround yourself with friends and family.
2. Take up a hobby/activity that gets you our of your own head -- rock climbing, martial arts, yoga, boxing, etc. This will give your mind time to rest. they force you to intensely focus.
3. Accept that, for the moment, your're wife is in a fog. She'll lie, cheat and steal. She can't be reasoned with. She may or may no snap out of her fog. When you're ready she can be made to feel the consequences of her actions. That may or may not work. Right now she's not feeling the consequences for her actions, eventually she will. All in good time. What you are focusing on now is getting your game back.
4. Realize you have time on your side. IF you take too long, you'll be worn down. But for now take a break from the drama. Regather your resources and prepare for battle!
5. DO NOT move out of your own home. This may affect custody issues in the future if things go south.
6. See a competent family law attorney. This doesn't mean you are getting a divorce. But it does mean you need to know your rights and learn how to protect your situation.
7. As an exercise, ask yourself if the marriage went south, what would YOU want? Custody of the children? The house? Shared custody? 50/50? This way, if she decides to pull the plug on the marriage then, at least, you know what you want and are prepared to get it. Don't getting dragged kicking and screaming into a divorce. You may win back your wife or you may not. You need to realize that if the worse comes to pass, you'll survive. What's most paralyzing now is your fear of losing your family. The worst case scenario is your children live in a broken home and you stop being married to a cheater and pathological liar. Divorce is bad for children -- all the studies show it. However what's worse is you remaining in an abusive marriage where you are cuckolded and psychologically emasculated daily. Your health with collapse if you put up with it long term. I thought a divorce was a death sentence -- but it's not. The best case scenario is your restore your marriage, the next best case is your divorce with dignity and rebuild a life for yourself. The worst case if you keep your head in the sand, get emotionally and physically sick, and eventually get dragged into a financial ruinous divorce and remain bitter for years. Think of options, A, B and C. Work on the fear and your actions will seem less reactive and tenuous. Stop walking on eggshells. Right now, you are acting like you are a footnote in your wife's life. In a healthy relationship, you are co-stars in the play. For now, your wife needs to be the footnote in YOUR life - that's necessary for your well-being. LIVE YOUR LIFE.
8. Stop chasing, begging and pleading for your marriage. Be strong, competent and mysterious. Until you are ready for more serious action, don't talk about the affair with her. Just be honest when she lies to you. You have to decide if the Last Resort Technique is appropriate now. Sounds like it may be. It's really for your own sanity.
9. You may want to stop snooping on a daily basis for your own mental health. But, perhaps once a week, you may want to gather evidence of the affair and keep yourself informed. Again, she's a pathological liar right now.
10. Take some steps to protect your assets. This is one way to remind her you know what's going on.
11. Go to the website: Chump Lady. She advocates a "choose now, me or him" take no prisoners approach to reconciliation. If you take that with a grain of salt, her other advice is helpful about taking care of yourself and protecting your assets. It's also funny AND will help you channel your anger/pain into constructive action.