Life feels dull now, but I still feel like if I can just prove to the world that I’m not weak and childlike, then maybe I can win in some small way

You'll discover in the years ahead that the secret is not caring what the world thinks. You don't need to prove to the world anything. You can find yourself, decide what values are important to you, and then live your live according to your definition of whats right. When people say "be true to yourself" this is what they're talking about.

There's a step beyond this too. When you know whats important to you, you make a real evaluation of who you are and what you do. You decide if your actions and behaviors match your values. If not, you work to make improvements in yourself. You do it because its important to you and not someone else. Improvements like these can be difficult adopt. You don't have to do it all overnight. Some improvements aren't a one-and-done but rather a way of living. I'm positive I'll go to my grave continuing to try to be a better version of myself, and I wouldn't have it any other way.

Each day take the action that, at the end of each day, makes you proud of yourself. The race is long, but only ever against the old version of yourself.