It sounds like you're in such a rough place. I've been thinking a lot about you, especially because my H has some tendencies similar to yours, though not as extreme. Mine also has this automatic blame response where whenever anything goes wrong, blame goes to the nearest person-- usually me-- though I will say this has been much improved over the past year.
I have also noticed that your H has improved in some of these areas quite a bit, like that weird mocking behavior is pretty much gone now, right? Also, I think it is really wonderful that you've been able to adjust your own responses (it has been an inspiration for me), like hearing him out when he's upset rather than making it about you and your emotional response to his behaviors (a pattern I also fell into quite a bit).
However... eventually, and I suspect this is where you are, you can make all the changes you want, and he will either be able to respond in kind, or not-- and then you do have a decision to make. I guess I just wonder if MC is an option for you two. It doesn't seem like he will be able to move past where he is right now without some level of professional help. He also has to truly desire change, and it sounds to me like you aren't sure he's able to pull out of whatever space he is in right now to truly care about how his actions are affecting you (and also your eldest) and commit to doing his part to changing these dynamics.
I do agree it is time for you to speak your truth and I was actually cheering when I read what you told him, especially the part about knowing he didn't want to hear it but was going to have to anyway. I'm hoping you can continue to take care of yourself as your first priority.
Thinking of you.
Me (46) H (42) M:14 T:18, D9 & D11 4/19 - 12/19: series of escalating BDs 9/20 - present: R and piecing
