I have to say my experience went a lot like B66's above. So similar - its eerie to read her words. I thought at first it WAS mental illness. When I realized that at least it was alcoholism (and maybe still mental illness, who knows?!) and could say the word out loud, I got to an Al-Anon meeting and a counselor. For me.
Because it became about me at that point. I identified the problem, called it what it was, and now it was my responsibility to fix it. At first I tried to fix HIM, but that didn't last long because he would just react badly and I got tired of the attacks when that happened. So I sucked it up and admitted my codie ways and starting working on fixing ME and here I am...separated from the RAH and happy again. And although I know he is not "happy", he is relieved I got off his butt and let him be.
Welcome to SR; find an Al-Anon meeting, keep reading, give yourself some time to process, stay safe, and keep focusing on you. If you don't take care of yourself right now, no one else will.
~T