Dear Mary,
I'm sorry to hear that you have a big problem. I have some suggestions for you. I think you should study hard first and (给你父母一个惊喜). And then you should talk about your problems with your parents and (告诉他们你的想法). At last, you should tell your parents that there is something important except learning. (如果你那样做), I think your parents may understand you.
Yours,
Anna