It is normal to lose about a hundred hairs a day, so the estimate of 500 hairs a day is definitely over the norm.
The inheritance configuration of male pattern loss is poorly understood. It used to be thought that it came from the mother's side through gene inheritance, called mitochondrial inheritance, but has since been found to be far more complicated than that. With this being said, even though no one in your family has had male pattern baldness, this could still be the early presentation of that condition.
If there are other symptoms associated with your hair loss, we'd want to do a complete battery of blood tests to make sure there's nothing internal that can account for that rapid loss- provided that you look healthy on the inside. We would then address the male pattern loss with topical options like Minoxidil, which is over the counter or more sophisticated options, such as oral Finasteride.
Incidentally, there's a new medication called Dutasteride, which is yet to be approved by the FDA for use in hair loss. It is a similar molecule to Finasteride and will likely be an even better agent for male pattern loss.