What is why am i so mean to my girlfriend?

As an AI language model, I cannot access your personal experiences or reasons for being mean to your girlfriend. However, being mean to someone close to you can have various underlying causes such as personal insecurities, unresolved issues, communication problems, power dynamics, and emotional distress. If you are struggling with being mean to your girlfriend, it is important to reflect on your thoughts and emotions and seek support from a therapist or trusted friend to improve your behavior and relationship.