With your combination of grades, rigor, and extracurriculars, you will be a competitive applicant at many colleges including Harvard. The parts of your application package you need to focus on are your letters of rec and essays as those will differentiate you from other applicants in a competitive applicant pool. I know students with similar accomplishments (e.g. international awards, research, excellent stats) who were shut out of the most selective private colleges because they failed to create a cohesive theme and narrative in their application.
You should be able to pursue your interests at any college that supports interdisciplinary learning and offers applied math, data science and neuroscience. The ability to tailor the major expands your options. A few colleges with the specific major: JHU, UChicago, and UC Berkeley.
Also, find a safety or two that you love and some match/target colleges where your combination of stats puts you near or above the 75th percentile for that college. Some colleges that could be matches for you: William and Mary, Boston University, UC Davis, and UPitt. Best of luck to you.