The feeling of "I'm not cool enough for Burning Man" makes 100% sense. I know many people who have keenly felt that. I've felt it myself off and on. If you let yourself fall into the wrong mindset it can definitely bring you down.
But some of my greatest inspiration from Burning Man comes from having learned how not to give into those insecurities, and to have let myself see with open eyes the supportive community that really is there and shows authentic enthusiasm for you just because you're you: no matter how uncool, introverted, shy, awkward, or whatever other non-sexy self-label you apply to yourself.
One of the greatest strengths of Burning Man's community at its best (in my opinion) is offering such unique support for people proudly being whoever they are. Even if they're uncool. Especially if they're uncool. You are loved and accepted simply because of who you are.
Yes, this sounds like hippie nonsense. Yes, it's not universally practiced and there are elements that don't buy into it. It's definitely not a walk in the park. But that magic is really there. I felt it through some combination of dumb luck and personal openness to the world and I'm deeply thankful to have found it.
Maybe your path can help you find that too, maybe not. I'm lucky to have found some amazing personal community there that continues to support me even in my weaker moments. But I assure you, as best as I'm able as random words here on a computer screen, that you could be a deeper fit in that community than you may realize. Maybe you'll never go there (and I'd be the last to judge you if you don't). But if so, it's not because you're not cool enough for the party.