What should I do with my life?

I'm confused about life, like most teenagers. Two months ago, I spent a week on a trip, traveling to a foreign country. When I returned, my entire family commenced treating me as if every move I make is wrong. My sister got a boyfriend, and now my parents are convinced that she is on the right path with her life because she spends every waking hour out of the house; her grades are also far lower than ever. They ask her how her exams are, and dismiss me. I have such a hard time keeping them happy with me though I conform to and exceed their standards of grades and I don't disobey them. I've also cultivated many passions but have no idea what to do, and now because of this new sibling rivalry, I feel an even greater need to create something with them. I love to write, I love fashion, I am an artist, but most of all, I adore music. My sister has started a band and performed, albeit briefly, in a musical for our high school. I have accomplished nothing. I plan to spend this summer with sewing lessons, building musical instruments (Yeah... Circuit boarding, electronics, and whatnot.) getting healthier, and continuing my voice lessons. I just want to accomplish something with my dreams, goals, and such. What step should I take to fulfill my standards, even if I can't quite achieve theirs?