This may not always be true, but I've noticed that often when someone does something "to" you that you do not like, they actually also are doing that same thing to themselves.
I know that some people seem to treat themselves better than they treat anyone else.
However, my instincts tell me that if you look more closely, you'll see that they are ignoring and not listening to you in the same way that they ignore and do not listen to their true selves.
Or they constantly question and doubt you just as they question and doubt themselves. Even if their own self-doubts are thickly cloaked in defensiveness and loud proclamations.
In this context, the following makes sense to me: "You must learn to love your self before you can love anyone else."