Will my mom miss/ regret how she treated me when I leave for college?

Maybe instead of concerning yourself with how she will feel, let's concern ourselves with how YOU will feel. Will you regret your actions once you are gone? Are you behaving in a way that makes you proud and makes you feel good about yourself? You cannot be responsible for her behavior. That would make you a codependent. You're only responsible for you. If you like you and feel good about how you are acting, then you'll be okay.