You did nothing wrong. He is thinking and he is being pulled in two different directions. Just keep him in your prayers.
The Lord is working on him and he is struggling with things. The OW is putting pressure on him and heavy pressure and that is a good thing.
He knows the right thing to do and the things you said, you were right in. It will give him some things to think about. He is talking garbage and you seen it for yourself. You have asked for his forgiveness, and no you weren't wrong to tell him that you were still waiting for him.
You did an excellent job and gave him some more things to think about. You are being a friend and you are trying to help him. He is scared of losing his kids and yet wants to be involved with the OW which in his heart he knows is wrong and deadly.
It is like having an addiction that you know one day is going to kill you but because you are feeding your flesh, you are finding it hard to walk away from. Keep praying that God gives him the strength to walk away from it and opens his spiritual eyes. Which he has started to do because he is saying more and more that he knows what he is doing is wrong.
The only way he is going to feel better is by getting rid of the sin (OW) and satan doesn't want him to do that. Your husband's eyes just have not been opened to that yet. Keep praying that they get opened.
I think that you have done an awesome job and you have been obedient to the Lord. There is also nothing wrong with letting him know that you are still there waiting for him. It gives him security in a sense. Whether he wants to admit it or not, you are a form of security to him.
You represent the goodness and the life that he is looking for, but doesn't feel worthy of having. So therefore, he stays with the OW, because she represents sin and for now that is what he feels he is worthy of. When he is around you, he is under conviction and when he is around her, he is under satan's control and satan can make the dirtiest thing look beautiful until he gets you where he wants you. Then the real thing comes to the surface. Pray that the Lord shows him this before it goes any further.