I did not understand your statement that you lost your 5 years. How? what do you mean by that? You are in 11th grade and you are aiming for Aerospace Engineering. It is very good that you are clear about what you want to do. Now just keep working really hard. Do systematic and disciplined work. You want to get AIR-1. It is really really a very big dream and to achieve such a dream I am sure you know that how much efforts will be required to put in. According to me to achieve this target one has to disconnect himself or herself from rest of the world and literally become a saint who lives in cave doing meditation day and night tirelessly.
All the very best.