this thread is based almost entirely on one of the biggest difficulties facing those who aspire to do well in mathematics. namely the confidence problem. we all know the extreme unlikelihood that we will ever do anything comparable to the work of abel, gauss, galois, riemann, dedekind, etc, etc... indeed it is discouraging even to begin to list the names that will almost certainly always be bigger than our own.
but the same problem faces people who want to become athletes, or artists, or newspapermen, or politicians, or salesmen. so if we still love our career path and want to pursue it, we have to summon up the courage to embark on a very difficult venture in which we have every chance of falling far short of our hopes and dreams. we have to maintain optimism and objectivity, to take satisfaction in small successes, and we need to learn not to let our mental health depend completely on every little sign of success or failure.
one thing that helps some of us, especially oldsters, is trying to teach and help other younger people. this helps us realize the long spectrum of learning that exists, and that we are not at the bottom of it, even if we are also not near the top.
ultimately we learn to work "for the glory of god", i.e. for enjoyment, not for personal aggrandizement. also it helps if we have a plan B, i.e. if not all our eggs are in the same basket. even david hilbert took a teaching certificate in case research did not work out for him. one good thing that can come from competition, or comparing our work with other stronger workers, is that it can teach us how to improve, and inspire us at least to do our own best.
i hope the OP has had some chance to grow and flourish, but i was frustrated that his high school was so short sighted as not to allow him to attend the university class that suited him better than high school. i would have appealed this with help from the university professor. perhaps he has since suffered some more setbacks and again faced the ongoing challenge of finding his place. i wish him well. he certainly has youth and intelligence on his side.