Receding hairline and thinning hair, and I'm only 17

[TheFirst17]

Hang in there! We are all apart of the same family, so to speak.
I know something like this can hinder your entire life.
And it's so sad, because the outside world could care less than you're balding - But you, as a person, can't come to grips with it.

I would move fast - in terms of talking with a doctor and making a number of appointments about it. And go from there.