There has been tons of great gouge, but I can't emphasize varsity sports enough.  I did MCJROTC and everything that came with it drill team, color guard etc.  When the time for a Navy scholarship came I didn't get one.  Varsity sports help alot.  I earned a  ROTC scholarship once at Tulane due to my grades and my technical major.  Tech majors will make getting a scholarship on the Navy side much easier.  My brother is in the same position I was and he also focused solely on JROTC.
 
Also, JROTC does brainwash you.  I felt like I had to go Marine Corps for the longest time, then the lightbulb went on, and I decided I had to FLY Navy!
 
Your motivation, drive, and determination for someone your age is extremely impressive.  Keep it up, never lose sight of your dreams, and you will go far.