Do you think this plan is possible?

Well I'm 14 years old, going to high school later this year, and I just want to be the best that I can be. My parents have asked me many times to become a doctor ever since I was little. I am somewhat interested in medicine, but also interested in law, criminology, athletics, and media. What I want to do is go to college at either Stanford, Northwestern, University of Illinois;Urbana-Champaign, or Machusetts Institute of Technology. I want to play football, as it has been my dream since I was little to become a NFL player. It's a long shot but I want to try. So what I'm going to do is finish college as what I happen to choose as my major/minor, and then play football in the NFL. Not trying to sound naive, but it's what I hope to happen. Then after I retire from the NFL, I hope to become the profession in which I chose to study in college. My question is: Do you think I have somewhat of a chance at this goal? Please only serious answers, and don't bring my hopes down too much. Also, what would I do offseason? And lastly, my dad's been forcing me to pick what I hope to be by the time I turn 15 (next April) so please help out and tell what I should do?