A lot of us are about 21 dude. It sucks man, but you're actually one of the lucky ones. If you start plain finasteride now, you'll probably be able to maintain most of what you have and even stand to fill it in. I would echo the sentiment that you probably don't need Rogaine yet, but Nizoral couldn't hurt. Don't be ashamed, there are plenty of 21 year olds walking around campus here who probably don't even know they are thinning (me being the psychopath that I am, notices EVERY dudes hair). Start finasteride and be happy that you don't have the uphill battle that most of us do here.