I felt the same for a while with my last boss, he is an emotional abuser and I'm told he is a psychopath. What helped initially was reading a book about what I went through. The book showed that people in my situation rationalize the signs away, and that I was being deliberately deceived to mask his abusive and manipulative actions.

I'm not sure what you experienced, but perhaps there's some literature on it that would help you understand it better.