I don't know what you are studying at school, but you need to do some research on addiction... affairs are addictions...
You need to keep CLOSE contact with OMW.
What kind of arrangement do you have with OM at all?
Has he promised to stay away from your wife? You need to go to OMW's house and talk to her to get HIM to commit to his wife and to stay away from yours.. if he WILL do that that's great... you have to keep an EYE on him still, but if he knows you are fighting for your marriage and his wife is too he may just leave your wife alone...
You need to keep in the middle of thi saffair, keep sticking your nose into it... do NOT trust that its going to just go away, you need to MONITOR this for at LEAST the next six months.
Keep tabs on your wife, get EVERYONE marriage-friendly to support you adn watch her as well...
Do NOT pursue your wife to commit to M or counselling... just go yourself and keep the affair out of your marriage for now...
Your wife needs at LEAST three months to get him out of her system before she's going to look at you twice... but they DO come back, your old wife WILL come back if you give her hte time and do the work.
She is in an ADDICTION right now... you need to maybe watch a TV show called INTERVENTION.. its a good sample of showing how people are during addiction.. it will give you hope and keep you from judging her harshly right now.
