The saying is wrong. I agree.
I have experienced what the saying is supposed to be though, and maybe they just played with the wording a little to make it sound less like you’re doing something wrong. For a lot of people, it should be “You can’t accept love from someone else until you’ve learned to stop hating yourself.”
I have had my love doubted, I have had my sanity doubted, by the person I loved, simply because he decided he was unlovable. Therefore, something was wrong with me, because I did love him.
Most insulting, the idea I had a place-holder-love. As in, I would love him until someone better came along. Ugh. Just a warning to people reading this, if you recognize this idea just realize this is a self-fulfilling prophecy if you keep it up long enough.