Dear Anon, it is sad to read your posting and I wonder if at your young age you have asked yourself if this is a healthy relationship. Is the physical looks you describe your strong hold for keeping your guy? Sounds like he has a lot of emotional issues of his own. Is this the partner you want to share your life with? Is SEX that important that you are willing to remain in what I call a toxic relationship? Or do you think you deserve better? At 19, love is a very confusing concept. Infatuation, lust and loneliness can be mixed up with a desire to love, give and nurture a healthy relationship.
My suggestion is to distance yourself from this relationship and allow him the time to grow up. Wouldn't you prefer to be with someone who respects you for more than your looks and is there to be your pillar of strength? Are you not deserving of that? Move on!