Hi MeowMix,
I always, always pushed myself for some unknown reasons. I started college at 16... always worked 2 jobs... felt like I had to push myself to further and further goals. People told me to relax, but it wasn't until my colon finally knocked me hard enough to make me realize that I have to be gentle now (hence my screen name).
We know stress adds to our problems. But it also keeps our bodies from healing and nurturing itself as it is supposed to. Eventually something will have to give. You sound very wise and self-aware; don't ignore your inner voice telling you to make a change in yourself. All the accomplishments in the world won't amount to anything if you don't have your health.
For me, I wish I had spoken to a therapist when I was younger to change my way of thinking about myself. Nothing short of that would have helped me because the pressure was too deep-seated. Good luck to you - you are lucky to know this about yourself at such a young age!