My husband had never cheated on any woman he dated until he crossed her path. He's a grown ass man and is responsible for his actions but I feel like if he hadn't crossed her path, he wouldn't have cheated on me. (please don't judge me, I'm sharing this based on the years of knowing him)
I sometimes think that having an extramarital affair is just another way of pursuing a high. You're just swapping one substance for another.
Some days, I feel like he cheated on me because he was misled and his judgment was clouded. So as a human being, he succumbed to the temptations and lost his integrity. By the time he realized what happened, damage had been done.
The same could be said about his choice to relapse.
It's pretty typical to blame the Other Woman for her actions, but at the end of the day, your husband was the one who made those vows to you. She didn't.
Your kids may be asking for their daddy because honestly they don't know any better.
I was physically abused as a child (it was our caretaker), and I did a lot of mental gymnastics to make my daily existence more bearable. I said to her plenty of times that I loved her too. As a result, I minimized the abuse for a long time. As a child, I thought when she beat me up it was my fault. At university, I was severely depressed and the administration had me on suicide watch. When I finally opened my mouth (I was in college by then), my sister said I was exaggerating because we had deserved it. She still talks to her abuser, and now she smokes pot and god knows what else to dull the pain. Her own daughters no longer live with her.
Perhaps your husband is truly sorry for what he did. What is he doing now to prove to you that he's the partner you deserve? Does he have a recovery plan? Or is he trying to sweep everything under the rug?