Strength, it must have been awful to hear that your husband told a relative that he hadn’t been happy in the marriage since the child were born. It’s such a disrespectful attitude considering all the changes and challenges you’ve had to adapt to in caring for the children, only you’ve taken on your responsibilities as an adult whilst he feels robbed of being a perpetual teenager — not a very grown up attitude. Even so, the upset of hearing that he has said he wanted out to someone else, and the shock that you were living a lie, that is, his lie to you that he was the happy husband and father, your “soulmate” as you believed. How crushing that must feel.
I’m afraid he probably has a different version of his “truth” depending on who he’s talking to. He wants to portray the “correct” version of himself to suit his audience. What he has told the OW about his feelings for you and the marriage are probably the mirror opposite of what he has told you. I would guess that you’ve both been played, and I would still hazard a guess that this is not his first infidelity. But this affair on its own is bad enough. It seems to show just how capable he is of compartmentalising his life, and if so, that is not a good sign. He’s used your goodwill and played you like a violin throughout this affair. You deserve to be treated much better than he has done.
You have shown amazing fortitude throughout, and you’ve been very tolerant and, I would say, kind to him when he really didn’t deserve your kindness and patience. I would be furious at being treated in this way. Where you find your grace and courage from, God only knows. But I think time is up for him. I would guess he’s never going to fully account for his behaviour and the way he abused your trust. He’ll change his story to suit what works best for him, and he’ll revise his history until he settles on a version that you find more palatable. Don’t fall for this! Why should you believe him now when he has deliberately and purposefully lied to you? Is he suddenly going to be rigorously honest as soon as OW boards her plane home?
From now on, the focus has to be on you and your life, and thinking about the kind of life you see yourself living. Don’t put him
in the frame. It’s the 180 philosophy now with the view of healing yourself and making a new life. (Assuming you are considering divorce now.) Its a very hard lesson to learn, I know, but your husband wasn’t the man you believed him to be. I’m so, so sorry for the pain of this situation.