My future career? Which passion to persue?

You can do both. My advice is to pursue the doctor career. You will make money to live on, raise a family and provide the essentials. However, you can still play the piano. Ever seen the show House? He plays the piano! And he's a doctor! You won't be famous, but you can still do what you love. Hey, who knows, you might end up going far with the music along with being a doctor. But deffinetly go into medicine!!!!