As for his life not sounding peachy, it probably isn't. He is in pain and he does have difficulties, but as I've said before, he has choices I don't. He has never done a school run, the supermarket, a washload. He chooses not to drive, but sees that as a luxury for me. He has no friends (which also worries me)and has ensured that I have none too. I'm hoping that I will be reassured that mental health services will pick up where I've left off. He is an intelligent man but all his life has relied on others.
This makes me really worried for you, because I don't think anyone will guarantee that mental health services will step in. But that shouldn't be a condition of you leaving. In any case, he would have to engage.
When you say he has choices you are absolutely correct, he has the choice to be abusive or not. He has the choice whether to help himself or not. He has the choice to stop blaming you for his health issues and stop taking it out on you. He is choosing to live in this misery and drag you down with him.
You are not responsible for him. You did not sign up for this. Husbands and wives nurse their spouses through all sorts, but that is not what is happening here, even though that is what he is trying to dress it up as.
It is going round and round, and no one can change it except you. It suits him as it is now, having his every need catered for and having literal witnesses to his misery. You have the choice and it sounds like you are about ready to make it. That is good. You will waver, it is incredibly difficult to do, but you CAN do it.
Can you imagine a life free of him? A life that is yours?