Can you get a perscription pill (besides birth control) without your parents knowing?

I'm ADHD. My first pill was Concerta, then that stopped working, and I went on Vyvanse. All my grades went up, and every teacher said that I had suddenly gone from a pessimist to an optimist. My mom and I got into a big fight in winter. She blaed it on my medication. Really, I was upset and crying about something that happened at school that ruined my freshman year. She switched me from Vyvanse to Focalin XR and I felt so terrible... I would flush my pills down the toilet. I was always bored, foriegn, annd empty-feeling. I cried about this switch. I couldn't take the Focalin XR for more than 5 straight days without an outburst. My mom said I was addicted to Vyvanse because I cried over it, which isn't true. I never took more than the dose I was told to. My mom threw away all the old pills. I did get an incline on my grades to straight A's because, right before semester exams in January, I learned that the only way to cope with the new person I had become was by making myself proud by getting good grades. On this medicine, I became completely achievment-oriented. My mom will never let me switch back, but I've been on this medicne long enough to want to be myself. I found myself on Vyvanse. I lost myself on Focalin XR. I know girls can get birth control without their parents knowing. Is there a way I can get Vyvanse? I do have a friend whose parents won't let himget a job, so he sells his Vyvanse (the same dose I was) for money. I have a job, so I could pay for it. However, it's not right, and I'd rather get a legal perscription from and M.D. I am very confident that I can maintain my grades. What do I do? How should I get the medicine?