I know what you're talking about. I used to be a very good art and history student, and then I very quickly realized I was largely innately talented at art and hit a wall in my ability because I was self-taught, and in history I realized I was lying my way through the classes, not doing any of the reading and then being good enough at knowing when to say something and when to shut up. It was really very discouraging, especially as this was a point in my life where I was having a lot of social problems and not really being able to tell if people genuinely liked me for who I was or if they were just nervously laughing and just kind of afraid of me.
The upside to all of this is that I discovered the sciences. Since then I've thrown myself into the deep end of things that I was too afraid to do before, like mathematics and the natural sciences.
So my advice to you would be to find something new that you don't know much about, but that interests you regardless. And hold on tight to it. Work hard at it and you will be good at it. People will be proud of your accomplishments. Try to ignore the negatives in life and focus on those positives.
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