Should I go into medicine?

I am a senior in high school and due to certain vicissitudes in my life I have begun to desire to change my personal values and stop slacking in school. All of this has led to an aspiration to possibly leave my dream of becoming a musician and instead become a doctor- perhaps an oncologists or a neurologists. However, I am unable to distinguish whether my newly found aspiration is based solely on the large salary or whether I actually have an adequate desire to enter into the above fields. I have always been fascinated with the brain and disease, But I am unsure whether I would enjoy being involve in said field. How can I logically differentiate my desire for a large salary from my interest in medicine to figure out what I should do for a living?