I posted today about this... and can relate to knowing but not being able to let go. I included an excerpt below. It was the hardest thing I've ever done.

You are experiencing abuse. Please seek help.

Work with a therapist. Explore what fears you have about leaving or what the purpose of keeping him is. Invest in yourself. Stay no contact, and fight him being in your mental space. I PROMISE you will feel better. And this will likely just get worse.

The thing is, I knew he was bad for me. I couldn't see a future with him. Our values didn't align. He didn't fit into the rest of my life. I had absolutely no trust for him. I grew to dislike him as a person. I had no self respect left. I hated the person I was with him and what he drew out in me. Feeding his ego became disingenuous. Even superficially, he was not as handsome, educated, stylish, or worldly as my past partners. He put a lot of emphasis on our sexual connection - and it was good - but even that lacked for me in a lot of areas that I couldn't communicate because of his fragile ego.

BUT I COULDN'T LET GO. It felt like an addiction. Things finally imploded and I left. I don't want to present myself as innocent. I was miserable to be around. I had no trust and questioned him. I couldn't forgive him, or leave him. I was negative. My reactions were emotionally charged.