I don't think we ever stop needing our parents' approval, whatever our ages... As for your dad always yelling at you, why is that? Is there a neutral third party who can sit you with you two and talk things out? A family counselor maybe? or family friend? It's funny how we are with our families most of our lives and yet we often don't deal with the issues we have with each other. I know it is hard to do though because many people are set in their ways or don't know how to deal with things on a healthy level.