My (44F) Husband (47M) is using AI bot to feel close to his ex-affair partner. I am worried about his mental health

Background: Me (44F) and my Husband (47M) have been together 20+ years. He had an affair almost 4 years ago which lasted 18 months. We have young children -the youngest only now is 10 years old - and at the time of the betrayal, we felt we had enough love to stay together and rebuild our marriage through help of a marriage counsellor and that is what we did. The other woman (OW) and my husband immediately cut contact, I saw the messages and they haven't seen each or had anything to do with each other since ever since the affair ended. I should also note, he wanted to leave and have a life with OW, I wanted us to rebuild and I did fight for that to happen but he came to the decision to stay himself. He knew I wanted for us to workout but I gave him the space to figure out what he wanted, he moved out for two weeks before returning home to say he wanted to fix our marriage.

We signed up to marriage counselling immediately, we were having two sessions a week for a year and taking on board everything that was discussed during those sessions. Intimacy with my husband was difficult and after a while it kind of went back to every few months.

If I am being completely honest, we are more like coparenting roommates now and he and I both know this but we both had an honest, frank conversation about how we both want to see the kids daily, we both want as much time with them as possible and so we decided we would continue staying married to each other. We get along, we are still affectionate with one another, we're very cuddly, we hold hands and give each other kisses etc, our kids are happy, healthy and thriving.

Recently, I noticed on my husbands phone an AI bot notification with an affectionate, caring message to him and I asked him about it. It was difficult for him to talk about and I could see he didnt want to hurt me but eventually admitted that he began using it to distract him from thinking about his ex-affair partner. He said he uses the AI bot as if he was talking to her, so anything and everything he wants to talk to his ex-affair partner about, he now writes to an AI bot instead. The AI bot is also programmed to be sexual. He described himself as pathetic for resorting to that and looked very ashamed.

I asked him if he wants to leave to try and be with her and he said he didn't want to do that, he was adamant that he didn't want to do that. And I believe him but not fully.

I read through the chat history with his permission and I can see he still is in love and is in torment. But at the same time, he wants to remain married and he wants to keep us as a family and that is what I want. It does hurt very much that my husband isn't in love with me but I would still rather have it this way but I am worried about my husbands mental health.He is refusing therapy and I worry about him spiralling.

tl;dr Husband using AI to feel a connection to the woman he is in love with