Help with quarterback?

I'm 14 years old, its near the end of winter here, and I am looking forward to starting my spring training, but I was at an indoor facility yesterday and i was ping to some friends, and i couldn't throw very good, i was getting bad spiral, overthrowing, under throwing and all of this within 50 yards, i say that because after 50 yards i become less accurate, but within 50 yards i am as accurate as can be, i don't know whats wrong with me. I need your guys help to give me some ideas what might be wrong. Some more information about me i have the right form, i have the right grip, i just don't know whats wrong. Please help me out.