Finally had a chance to get back online. One thing you need to remember is you are doing your best and that's all you can do. Don't beat yourself up over it. This is a crazy time for your family, but just focus on the here and now, the fact you are a person who has learned an enormous lesson and you know your family is the number one priority in your life.
Now as far as details about the affair.... many betrayed spouses have the VERY strong drive to know every single fact. I understand what you're husband is doing because I've been there and still have my radar out for any piece of info I can learn (sex details, what she wore, what they did, etc...). Although I've read it's important to talk about the affair, I think creating visual images (especially when the wounds are so raw) may not be the best thing at this time. And you'd be surprised how any little word can do that. The other day my husband merely mentioned that what they did was "dirty" and just that word created some ugly scenes in my head. After just hearing that one word I felt kind of ticked and wanted nothing to do with him the rest of the day.
I think when he does want details one thing you might consider doing is sharing what was negative (even if it's exaggerating). Think about what was negative about the whole experience. If it was uncomfortable or akward in any way. Whatever you can think of that was bad, bring that up. Even if the affair was the greatest sex in your life, think of what was bad in it. When people go into affairs they often "rewrite" the history of their marriages and focus on what was negative in them. This is what you need to do with the affair.
I sometimes will think that for my husband OW was the greatest experience in his life and that he lost his soulmate and now has to "settle" with me. Hearing the negative and ugly (even if it's just him "rewriting" it so I KNOW he sees it as negative and isn't missing OW (even if he was just convincing himself of this) would make me feel better.
But keep in mind, affairs take an average of 2 years to "work through." For some people it's quicker and for others longer. Hey, my husband's first affair was "only" a 3-month EA and it took me probably 5 years to get over!!!! I was really angry and mean for a long time.
By the way, a very good book you might want to take a look at and share with your husband is the following:
