I failed Ochem and I feel really bad?

Why is it so hard? God dammit. Especially when my peers have 80...even 90 percents? I was just barely ping, and today I gave myself a 1.5 grade. I got a 48% on the ACS organic chemistry final. What the hell? I studied hard too...Perhaps my major biochemistry is not right for me? What should I do? I am 19 years of age, guy.