Oh rollcall I feel your pain. Its hard to imagine anything more devastating than being betrayed by the man you trusted with your life. But having your kids meet and spend time with and possibly grow to like or love the object of that pain is debilitating.
I have 4 kids and so far they do not know why we are getting divorced. My STBX promised me over and over that he wasn't with the OW anymore, would never be with her, our kids would never meet her, I wouldn't be reminded of the pain. I recently found out that was all more lies. I now am preparing and dreading the day the kids meet her. He is still keeping her secret from them but some of them have met her through his work, as a "friend".
I have no idea how to deal with this either. I was starting to look forward to a future where this was all behind me and I could move on. But when you are tied together by children - so many in your case (!), there seems to be no end to the pain.
I've found comfort in knowing that I will always be their only mother and I try to be the best, steadiest, consistently honorable mother I can be. I plan to teach them right from wrong, the value or a trusting loving commitment, and how important it is to be happy - but not at the expense of everyone that loves you.
I hope you have friends and family and counseling to help you through. I finally started anti-depressants and it has helped to make me stronger and see the truth. But the pain will be there for quite a while.
Good luck to you and your kids.
Me BS 44, Him WS 44
Married 17 yrs 4 kids-3,6,10,15
Day 5/23/13 divorcing