Personally, I don't think YOU can raise the happiness bar for both of you. You can only do that for yourself, as you said...he owns his unhappiness....it's up to him to raise the bar for himself.
I believe at some point you have to stop empathizing and sympathizing if he chooses to not make changes to make himself happy.
Haphazard, you do realize don't you that he's getting angry at you because you aren't enabling his behavior. You are doing what you need to in order to take care of yourself, as you should, and not allowing him to drag you down with him....this is great for you (and it's what you need to do), but he won't like it....because as I said, you are discontinuing being his enabler.
That is why I say....YOU cannot raise the bar for both of you. If he chooses to live in misery, you have no control over that...but you do have control over what you do.
