Cheaters Anonymous Community Group
This is a support group for cheating spouses looking for understanding and strength. Betrayed spouses are welcome to post ONLY if they can do so in a supportive manner (no bashing...these posts will be deleted), and please do not comment on 'Cheaters Only' posts.

If it is hurt, then the storm will be worst at the beginning. If it is hurt, he's struggling with the pieces as much as you are. The best thing to do is remind yourself that regardless of what he threatens, he cannot legally take your children from you unless you let him. Unfortunately, that is not an uncommon threat when marriages are on rocky ground. I find it to be horrible and shameful, but that's primarily because I have seen what happens to kids who get put in the middle between parents. If he's expressing hurt, he might be saying that because that's the only thing he can think of to make you think about a loss similar to the one he is feeling. If it's hurt, then try to remain calm at home, show remorse, and don't blow up at him. Come here if you need to vent. And focus on the parts of your life that may have been neglected during the A. Focus on being a good mother to your kids, and in expressing through actions more than words that you love them.
The whole mess an affair causes looks insurmountable when taken all at once. The key is small steps. Small things will make you move forward just a bit at a time. There's dinner to tackle, and laundry. There are kids to tuck in and sometimes a warden is needed to make certain teeth get brushed. There are little parts of your life like a hobby or a friend that might need some nurturing. Define who and what you want to be, and then take small steps to become that person. Regardless of what happens in your marriage, you can come out of this a better and wiser person.
I'm so sorry that it seems he is moving away from reconciliation and rebuilding. Hopefully this is a temporary set back and rebuilding can get underway. All I can say is to keep doing things to try to show him your heart and show him that you are working on yourself and are willing to do whatever it takes.
1 D for denial -- this stage is marked by shock and disbelief
2 A for anger -- mad at the person, the world, yourself. If he is here, you will feel some hate at times.
3 D for depression -- this is the most difficult one, and many prefer to life in denial or anger, as both feel better than depression
4 A for acceptance -- sorry, but you cannot rush this stage. It takes time, but is achievable.
So my point is understand he will be angry at you, the other person, himself, the world, and it will erupt as hate at times. Just keep refocusing you understand his anger, but also telling him there are lines that are not acceptable to cross.
Whether he likes it or not, your affair has changed him and he will need to assimilate it and who he is now that he is the spouse of someone who did something he never thought he would have to deal with. Like you said in your last line, he is being forced to learn how to cope with it.
Both of you can learn new coping, as many of us have survived this mess and are proof you can do so.