If I could just chime in...if you don't know who you are (how powerful you are), then sure, you might end up depending on someone else for love, and that is unattractive. And if your ex DOES comes back into the same exact situation (that is, you have not changed your thoughts and beliefs and feelings, the state you operate from), then it's quite probable you'll be stuck in another unhealthy relationship with him.
But we are manifesting all the time, self-love or no self-love. (whatever the heck that actually is). Like Mici and Sanshi said, you could absolutely hate yourself, but if you hate yourself and yet imagine and believe that your ex is absolutely obsessed with you, or that he is deeply in love with you, then that is what will transpire in your world.
I think the reason people equate "loving oneself" with "getting ex back" is because when you are in that state, the state of feeling good about YOU, then your thoughts and imaginings automatically become "I am loveable, I am awesome...therefore, *x must love me and think I'm awesome".