Mrs. distressedhubby - Welcome to the system for the survivors of emotional nuclear holocaust. Yes, there is survival, but even better than that, there is recovery and the rebuilding of a better and more loving marriage centered in Christ's love. I say that because I read a post of your husband's referring to your "pastor" as a potential source of help. If I'm offbase on you two being believers, please accept my apology.
First things first, I think I understand the turmoil going on in your mind as my wife was involved in a 6 year affair and planning on a divorce so she could marry the OM. "Devastation" and "nuclear holocaust" almost seem to be understatements for the emotional flood and doubts that are released upon discovery.
Second, I want you to know that if you are both willing to try to get through this, you CAN and WILL recover. Your marriage will never be the same again, but it can be better than it was when you were both stumbling along just thinking all was fine (or feeling "second best" as I'm sure was one of the motivators of your husband's infidelity. It was for my wife too.). Now, you have the opportunity (sadly that it took "this") to really begin to understand what Love and Obedience to God are all about.
All that is somewhat in the future for you and you both need a "place to start." So let me recommend a few things to help you get started.
1) Read. There is much you both need to learn about what happened, why things happen, what can be done to recover from such a blow the marriage. I'd recommmend two books to begin with.
Torn Asunder by Dave Carder and
Surviving An Affair by Willard Harley (the founder of this site).
2) Joint Marital Counseling. On the assumption that you are both believers, I cannot emphasize strongly enough that you both need to be in joint Christian Marital Counseling. The "guide" through this morass of emotions is essential.
Let me caution you though. You need a trained Counselor who is dedicated to saving marriages and helping you both to be obedient to God's commands. If you'd like some help in this area I will give you a link to a terrific counseling organization, many of the counselors provide their services at no charge as part of their ministry. You can log onto their website and search for counselors in your area.
National Association of Nouthetic Counselors In addition, I will give you a link to a thread I started after we'd been in recovery for a year. It's a few pages in length, but you might find some things in there (along with a list of many more reading suggestions) that may be helpful to you now, and as you progress through the healing process.
Forgive? Trust? Really? Lastly, it might also be easier if you registered your own Member name. That way we can tell WHO is posting, because you are both going to need some support, sometimes the same and sometimes different.
God bless and guide you through this deep and dark valley and keep you safely in His hand.