Look for the reason you scored a low grade. You did all you can to gain the knowledge and you've gain it. You answered your own way and you are perfect like that.
Good grades means alot but the knowledge you're aqcuiring is more important. Inventors are thos that don't take their education seriously. You're serious, you are going to become a great inventor and that grade does not matter at all.
Make plans to improve what you can improve. Meet with relevent people that can help your plan work. Evaluate your achievement and appreciate the level you are.
