I know exactly what you are talking about.
At the very end of my relationship I wanted my husband (now ex) out of the house more then anything in the world. No part of me questioned what I personally wanted for myself. He left once after carrying on for hours and I started crying a river as I watched him go. My heart was breaking. It occured to me, at that moment, that I was not even crying for myself. My heart was breaking because I thought he felt unloved and I caused that. The emotion was like a desperate and panicy need to make sure he didn't feel unloved or unwanted, despite the fact that love, respect, and even basic tolerance had left that relationship long ago. I couldn't feel anything for myself except extreme mental confusion.
It was a bit of a turning point because I realized that I had issues. I'm not saying you are at that point. I had gone most the way down the slippery slope of living with alcoholism - and it wasn't pretty. It is my long winded way of saying - I got the book 'Codependnet No More' by Melody Beattie. I did not identify myself as co-dependent (opposite actually), but then I read the book, twice.