I'm not sure what I can say. I remember feeling like you - and I stayed around for a long time after.
Things got worse with him, of course, but my confusion and depression got worse too. Finally things *for me* got so bad due to trying to manage it all and due to living in that weird place where I was trying to deny reality in order to live my fantasy - or talk myself into accepting something that I found unacceptable, that I had hit my bottom. That weird space left me consumed with rage and resentment and I was becoming less functional then him in some ways.
So I left then. I'm not sure what I could have heard 3yrs, or 5yrs, prior. I wish I could go back in time and start al-anon and seek some individual counseling to untangle the feelings of guilt, obligation, fantasy thinking versus reality, etc. I may have left sooner and I think for sure the leaving would have been less crazy making - maybe not. It is never an easy thing. My children would have been better off.
So I guess that would be my recommendation to you. Al-anon (which doesn't sound like a super option - I also found SR amazingly helpful) and counseling. I read the stickies at the top a lot and I found the book Codependent No More really good too.