So sorry about the hard conversations and realizations. Hugs....
Now, for some suggestions (maybe come back to these in a few days):
Stop telling H you want to reconcile. He knows. Stop asking him rhetorical questions you don't want to hear the answer to. And, for sure stop involving HIS parents (very inappropriate).
Every time you do any of those things, you push him firmly into OWs arms, and, especially by involving his parents, you make it much harder for him to end that R if he ever wants to. Your actions are painting him into a corner. Change your behavior.
No, do NOT rush to H or his parents to let them know you are changing your behavior. Just change it.
Stop with the drama. Stop with trying to get H's parents to fix things. Stop trying to get H to have a lightbulb turn on in his head.
Good job choosing to let go. Good job identifying boundaries that will help you with that.
(1) Divorce is business. You are quite right to be worried about H taking advantage of you. You should not be making business decisions while you are worried about how he will react. At the same time, in terms of financial/parenting arrangements, NOW is the time that H will be most generous. He will get less and less generous as time goes by. I strongly suggest you get a lawyer and handle ALL details through the lawyer. Do not talk about the stuff with H. Just don't. It is not good for you or your kids. It will NOT help your M to discuss the D terms with H. Let your L handle it. In your place, I would as quickly as possible get a legally binding financial/parenting agreement in place.
(2) Unless it is a legal or safety issue, stop trying to control H's parenting decisions. It is fine to share/report your concerns. It is fine to say "no overnights" and see what happens. But, H will do what he will do. Until you have a legal agreement, fighting his choices is pointless.
(3) There really is no point in demonizing his GF. The A started after you were separated. H was willing to have an A even though he was married with 3 young children. AND he had a deep moral commitment to YOU. GF did not. His is the greater wrong. GF is neither the source of the problems in your M nor the cause of your D.
(4) Take a lot of space, a LOT of space. Use email or text. Discuss business matters only. STOP sharing personal info with H. STOP telling him how he needs to fix himself. STOP using him or his family as any kind of support. You have got to work on independence. Build a strong support network and use it. Aim for DISTANCE and STRENGTH and FUN.
(5) Do not EVER mention the camping trip again except to your L or IC or FC. For one thing, you knew full well that OW would be on the trip and you CHOSE to consent. Do NOT expect H to manage your pain for you. He is not effectively your H, he is not your friend. It is really not his problem that his choice to move forward in a different R hurts you. It is not his job to fix it. It is not his job to manage his life so it works better for you emotionally. It IS HIS JOB to do what is best for the kids. I'm sorry the camping trip hurt you. I can certainly understand why it would. But, the problem that is relevant is that it is TOO SOON and conditions are TOO UNSTABLE to expose the kids to OW. When H says he doesn't understand why, DON'T point to your own pain. Again, it is NOT his problem, really. I know that hurts to hear, but it is true. It is inappropriate for you to expect him to manage your pain. Rather, try something like this: "H, we seem to disagree as to what is healthy for the kids right now. My concern about the involvement of OW in their lives so soon is that it will hurt them. But maybe I'm wrong. Let's go to a FC and develop a strategy that makes sense to us both in terms of the kids' interests."
The best thing you can do is to let go and work on not being angry, to aim for compassion and forgiveness. You are headed that way. Everything WILL be better, one way or another, your life will be better in the future than you ever imagined it could be even pre-bomb.
Do three things for yourself today and tell me what they are.
