I'm lost and don't know what to do. I'm unhappy with myself even though others say i live the life. Advice?

Im 15 and not happy with myself. I might be popular and have the looks but thats not what lifes about. Its fun and i wouldnt wanna lose those traits but its not getting me anywhere. I have a lot of friends but i like to think of them as "fake". Fake as in they only like me because im popular. I have one person that i can turn to and talk about things with but our friendship is fading. Stress is hard to deal with. Ive began failing school every since ive had this "unhappy" feeling. Ive also lost interest in baskeball. My parents are always yelling at me about my grades and how i dont know if i wanna play basketball. Theres only one thing i like to do but i dont even know if im good at it. But to get to the point. Im failing school..feeling unhappy..feel isolated at times and i feel like no one actually cares about how i feel on the inside. I wanna cry sometimes because i feel like i need to be someone more then who i am. I dont have "real" friends. I dont know what it takes to please others. I dont even know how to fully explain how i feel on the inside.