I guess I am unclear as to why you think your H feels you will punish him in a divorce? Has he ever said anything like that or is it simply what you think? If he feels being punished is being accountable for his children and his obligations then I guess I would say too bad for him.
I would ask you to at least think about the following:
You seem to see your H through your point of view only. I did that for a long time with my H so I understand exactly how difficult it is to *really* step in their shoes. You say you want your H to break up with you properly? Is the proper way the way you deem proper? Maybe he felt he has broken up with you properly. IMO the words are irrelevant, it's the actions that matter. When one spouse bomb drops, moves out suddenly and begins to acclimate the children to this new life that is about as blunt as you can be in a breakup.
I understand you yearn for open, honest and healing communication with your H but if he doesn't want to participate, he won't and even a IC won't get him to do a thing he doesn't want to go. Why? Because WAS are terrified to give any "false hope" to a LBS.
You will eventually have to forgive yourself. It's not an easy thing to do and something we all work at.
Don't be so sure though that a divorce decree will make things easier. Detaching and letting go is not easier once the legalities are over. That is why you need to be working on that now. Detaching should be your main focus. Once you stop caring what your H thinks or does (at least to the degree you do) things will not seem so difficult and DB might be easier and more natural for you.
Don't get worn down. Don't allow it to happen. I shudder when I hear that phrase. It's awful.