We are perpetual students, the process to fully grasp self love comes from deep within you.
What do you like the most about you? I've seen that people who struggle with self love are actually very unique, they fail to love themselves because they don't accept their special traits in a sense. Society makes it so being different is a bad thing.
As far as forgiving yourself, stop thinking about the past and be present. The new version of you has nothing to do with your old self, let go!