How can I get my Girlfriends parents to lat me date her again?

I am a 17 year old male, who is dating a wonderful 16 year old girl. We have been dating for over 9 months now, and its been very happy between us this entire time ( no fighting included) We use to see each other everyday of summer, frequently throughout school days, and everyday at school. we love to see each other even in between classes, and at lunch. I never felt like I saw her too much. She has a lot going for her - good looks, school, she is a state champion at skiing, and even how optimistic she is… We both are accepted as a couple by the entire school, our friends grow with us all the time, and we act like best friends. We try to live life including each other frequently. After 6 months of dating we had sex. Her parents quickly found out after searching her room and finding birth control. we were trying to be safe and got caught. They do not want me around anymore( have had dinner with them before even) , because they do not “want her around trouble”They have said things like “fck you” and “slut” to her. The parents were high school sweet hearts, you think we would get a little compassion? They have even drug tested me before, and I passed. They take away HER car, cell, computer now because they dont want her contacting me. We still like each other, and want to date, just sucks only seeing her at school. How can these parents be convinced we should date? I have tried sending them some letters to get my point across, explaining we can be responsible. They all of a sudden dont think college will happen for her. This is the only black part of my life I am trying to solve. I just want them to understand they should let us date until we break up. Because we dont do anything negative to the community, only make ourselves happier.