Im 23 now just had one 4 months ago.
With your loss, I would not touch your crown at all. Get on meds, and if after consults you decide its for you, do a procedure for the front only. Hopefully the meds will stabilize your crown loss, and at least slow it down. Definitely do not put any grafts in the crown I'd say. Also if youre self concious, look into some concealers. Dermatch works quite well.