My mom is intolerable!! (No, I promise I'm not a bratty teenager)?

its good that you understand she is the way she is because of who she is with her set of life experiences. If she's influencing you and you recognize it then you can do something about how you are. If you need help coping with her, find some help - school counselor or find another therapist. Do it for you. And yes, when you are 18, you very well may have to make your space from your mom.