Just passed 3 years since the true confession was made.
It is a long, long, long road. I can say that it has been worth it, reconciliation that is, but it was a close run thing several times.
Divorce would have been so much simpler to do.
what if he says 'sorry but I am leaving you for her'
If he does, tell him
"She's welcome to you, but she can't fix what is wrong with you either, and I hope you don't hurt her like you hurt me."
You can't control that, any more than you can control a person's decision to have an affair or their lack of a decision to decline one. What you can do is take care of the children, take care of yourself, and let him do whatever he is going to do, or not going to do, while you do what you must and set clear boundaries for him in your relationship.
One thing, so hard to realize, so hard to deal with, is the simple fact that your WS is far more messed up than they appear. People who are psychologically healthy don't do this to other people. It is cruel. It is hateful. It is destructive. It is sadistic at some level. Yet, they do it, like a psychopath strangling one of their victims. TT is the same. They do it because of their internal mess that they are not managing constructively. So many better options than infidelity, than cheating, but they pick this route.
Their road to healing is longer, and they can hold you back from yours because it is an ongoing struggle and they continue to inflict further wounds by TT and their other actions.
They are broken. If you reconcile, you will realize how broken after 2-5 years.
My wife got the message, fairly early on, speaking of boundaries, that any further lying was the end of our relationship.
It took her a longer to get the message that withholding information was going to do the same, and even longer to get the message that any secrets would do the same. Privacy was one thing, secrecy was another.
It took a lot of work and practice for her to realize that her focus had to be our marriage, me, the kids, our business, our hobbies, our activities, our needs, our wants...and that had to be, and remain, a priority each day. Other peoples needs and wants needed to take a back seat. That she needed to recognize the severity of the hurt she had inflicted. The last near divorce episode was around 15 months ago, when a friend of hers wanted to get her involved in helping with the friend's husband's weight loss, and another of her female friends chimed in that they wanted their husband to lose weight as well.
She tells me this, calmly, and tells me that she has this great idea, to have a competition with him and the other spouse, both spouses of friends, because she wanted to lose weight as well, all three of them. I sat there and listened to this, incredulous, then I blew up. I pointed out that just a few years ago she had "helped" an acquaintance with his needs, which included sucking his cock, fucking him, and spending time with him while I was exhausted and coming home to an empty house. Now, to remind me of all this, she gets involved in this? I pointed out that if the husbands really want to lose weight, they can go to weight watchers, they don't need my wife to help them lose weight, they can work with their wives, and their wives, my wife's friends, don't need any other woman to motivate their husbands to do anything. Nor, did I need my wife to be motivating any other man to do anything, anything at all, after what she'd done.
Good luck.