Flyaways:
1. Don't worry about academic achievement, the fact that you can string words together and post on here means you have enough brains to be a pilot.
2. Go for it. I suffered from under confidence as a youngster and I probably wasted about 15 years of my life before I reached the eureka moment of 'Hey, if he can do it so can I, and I can do it better.' Mind you as a downside I most certainly don't suffer fools gladly now....