All through my high school year, I kept telling myself,
it will all be different soon and it was. Just hang in there, keep your grades up and do your best... trust me I've been there. You may not agree with it, but if you want to achieve your goals its best to keep your grades up, like you've been doing. I'm lucky my eyes have been opened to Avatar after high school, otherwise things would be very very very different for me now. In the trade school I'm going to all I have to do is go to school for about 6 1/2 hours a day, and I love it there because its what I want to do, it's something I love. And Colonel/Cyan, you said you wanted to become a film director, thats amazing. I loved film; I've made lots of movies, even won a few awards at school film festivals including Best Screenplay, Best Director, and Best Overall Film (sorry I had to brag for a second). I wanted to become a movie director at my career, but alas, things were very expensive if I wanted to up my movies; cameras that cost a few thousand, new computers with expensive editing software and special effects programs, the microphones, cables, cast and crew... so I went to the automotive industry to have a very good income and on the side be an independent film maker, and maybe later on in my life become a professional movie director. Not saying this to affect your career decision, but I was somewhat on the same boat as you. If you film a movie let me know, I'll help you out
But like I said, hang in there, keep your head up, and soon you'll be doing what you love