Slow down here. You are getting scared and the fear is getting in your way of hearing what the Lord is telling you to do. You are trying to come up with so many different ways of how you can jolt him into reality.
Problem is, nothing you say or do is going to affect him in the way that you want, because he is not thinking like he should be.
He is starting to reap what he has sown. The Lord is allowing this to happen in order to teach him a lesson. In order to get him to repent for what he has done and you can not get in the way of this. The Lord is going to continue to dump guilt and shame on your husband until he gets his life right.
You can help your husband out the most by getting on your knees and praying for the Lord to help guide him through. Get back off the rollercoaster and just watch. You may have to stand in front of him and give him an ultimatum and then you may not have to. Only the Lord knows exactly what you are going to have to do and when you are going to have to do it.
Yes, they do go back and visit all of the stages and they have to close the doors on them. So right now, you have to get off of the roller coaster and let him go through this. Have you ever tried to quit a bad habit of your own? Have you ever asked the Lord to help you to stop doing something and you felt the peace from being released by it and then all of a sudden the next day it is thrown in your face?
That is what is happening to your husband. He made a choice to come home and satan is throwing everything at him to make him think that it was the wrong decision. He is throwing temptation in his face, talking in his ear and doing everything that he can to destroy your family. He is putting doubt and fear into you because if he can't get your husband to walk, then he is going to get you to push him out.
I hope that I explain this right and I don't mean to go over your head and I'm sorry if I do, but your fight is not with your husband or the OW. It is with satan and his schemes to destroy both of you. Your husband did the right thing by coming home and he did come home to work on the marriage, but satan is confusing him. He is the author of confusion and he is working on you at the same time. Go and read 1 & 2 Corinthians and 1 & 2 Thessalonians.
You can use any tactic that you want to get him to wake up, but it may not wake him up but push him out the door instead. You have to concentrate on you and pray for the both of you. Your husband is fighting for all he is worth right now to keep from drowning. He is looking to you for the answer, although it is coming out in anger, he is wanting you to make the decision for him. Don't make that decision. It is his alone to make. If you push it either way, then the burden is put on your shoulders and that is not where it belongs. It belongs on his shoulders and the decision belongs on him as well.
Do not try to solve this for him or try to fix it for him. He is like a fish out of water. Gasping for air and trying to get back to where he thinks it is safe. For the first time in his life he is having to face himself and does not like what he is seeing. He is willing to settle for the worst because that is what he thinks he deserves.
Stand firm in what you believe in and hang on because this is going to be a bumpy ride.
