I know exactly how you feel man. I started losing my hair when I was around 16, I am 19 now. I tried all sorts of things. Creams, pills, home remedies. None of it worked. Then I had insecurities about my head shape. Although I have gotten over my balding, I still have moments in which I think "****, I'm too young to be losing my hair". But then I think of the many people out there, that are missing an arm, a leg, or one of their senses. That's when I realize how fortunate I am. That the only thing I've lost is my hair. It may sound cheesy or stupid, but it's true man. Just hang in there bro, as Mr. Razor X said things will get better.
You don't look like a cancer patient man. As many of the guys suggested, hitting the gym will make you feel more confident. Good luck
Square your shoulders and shave the hair. You only have to please yourself and it WILL make you feel better. Do it and don't look back. Who give a care what your friends think...they will make a few comments and then it is a nonevent. Do it now. You will feel soooooo much better when you do.