HELP! My hair is falling out!!!?

I'm 19 and it started a month ago. My hair is falling out in excessive amounts. The Dr. just gave me some hair vitamins and some special shampoo. But what if it's hereditary?! All my aunts and uncles from my mothers side lost their hair and now have thin hair. My aunts are even almost bald! I'm only 19!!!!! ): Can I reverse hereditary hair loss? if that's even the case?!