My question involves education law in the State of:

I am need of some advice

Few days ago my school accused me of doing drugs ,My friends are influenced by wronge things that does not mean I am also influenced by these stuff too ,the day I got accused I got a drug test done and it came out -ve and I showed this to my parents and the school and they still don't this they believe me .So now the big issue in hand is that my exams got over 3 days ago and when i went and had a talk with my teacher they said I have not qualified for the next grade and I have to change my school and repeat ,those guys even refused to show me my marks . Are they trying to throw me out of the school because I got accused of nonsense stuff ? What can I do about this? I hate my school now.