High blood pressure at 18 years old?

I am 18 years old and i have high blood pressure, got it from hereditary. I've been ranging in the .. 133/77. I know this is bad since i am so young. I am VERY active. I run a couple miles daily, play tennis for hours, and other sports like football, soccer, ect. You would think that I am a professional athlete because i spend atleast 6-7 hours a day doing exercise activities. Also, the ONLY thing i drink is water (about 1 1/2 gallons a day) because i sweat alot and i need all the water. Why isn't my blood pressure decreasing?!?