Ugh, I'm very sorry. Male pattern baldness is indeed often hereditary. What about some of the hair growth products like 'rogaine'. Have you tried any of those?
Good time NOW to try Rogaine. The younger you are, the more recent the hair loss, the better it works. Hair loss as early as the late teens is rare but does happen in an otherwise healthy individual. Just see a dermatologist to confirm this hair loss is hereditary and not from a dermatosis.