How to get my mom to let go?

Im 15, and my mother is so controoling its almost unbearable. I have always wanted one thing in my life and thats to be able to drive. Now that im of age to obtain my permit my mother refuses because i had to go to summer school for a week. i got it over and done with. Im very successful with school and i have a highly active social life which she tries to control all the time. I havent been able to go anywhere in the past year because apparently my grades havent been up to her standards. Also the only reason why i had to go to summer school was because i was struggling with that subject. I did look for some tutoring but no savior. She says that im not interested in my future as much as i should be which is a crock of s*** because i have almost my entire life planned out. I currently have more money than and other teenager because i save almost every penny. Im only a sophmore and i already am talking to coast guard recruiters and im finding out what colleges there going to pay for. I dont understand why i cant do anything when i only slipped up once. It doesnt make sense because i am very eager for my future as well as planning for it. I just need some advice to get her off my back cause if she doesnt ill probably have a mental breakdown. Im the type of person to hold everything inside cause im not one to share. I just have no where else to turn because even my dad has to legit ask her if he can wipe his ***. which is absolutley pathetic. She is the most controoling person i have ever met and it needs to stop or even just easen up. I need ideas about what to do and how to let her accept that im growing up and she needs to let me be me.