What is is it normal that my girlfriend hits me?

No, it is not normal or acceptable for your girlfriend to hit you. Physical violence is a form of domestic abuse and can have serious consequences for both parties involved. It is important for you to seek help and support if you are in an abusive relationship. You can reach out to domestic violence hotlines or organizations for assistance and guidance on how to safely leave the relationship. Remember, you deserve to be in a healthy and safe relationship.