Just catching up with your news, Dolly and I am so sorry. I'm one of the sisters on here who has been through it - and now have come out the other end. A few feathers are slightly ruffled still and the lines on the face a bit more pronounced, but life is much, much better 
But you have so much to go through before this stage - and one thing I am positive of is that he's going to be crawling back pretty soon.
The big question is - do you want him back? And if so, you know life will never be the same again and it will be a long, hard slog. But that is your choice to make, no-one elses.
I took mine back, but then found him still at it. Once I thought a mistake (I know, stupid me!), but not twice. And not an affair that lasted 13 months. But I thought I loved him so much that we could survive. But the trust had gone and that, he said, was why he went back to her. She gave him the elbow as soon as I'd kicked him out the second time - he was just a bit of fun. Karma, love, karma!
I dislike this man who purports to be your husband immensely - as I do any other cheating spouses - because of what he has put you and your babies through. His little fantasy life with the OW is now becoming a reality and that is soooo different as they find out.
You have everyone on here's admiration and sympathy and take your strength from everyone who offers it - keep your friends and family close, they will be of help.
Keep talking, get it off your chest - and yes, you will have good days, terrible days - and even some great days. Those emotions have to come out, don't keep em trapped inside.
Try not to reply to his texts any more than you need to, he is loving the attention he is getting from you.
Take care of yourself and your babies - and welcome to Jasper xx