I honestly think you have some misconceptions. I don’t even think that the typical school activities and leadership roles are as important as you think, even at highly selective schools. I think most colleges value authenticity in an application. Many schools are focused on assembling an interesting class, with diverse talents, background and perspectives.
Don’t “pretend” anything!
What are you genuinely interested in? What do you do while home? Is there an interest you pursue on your own, outside of school, even if by yourself and at home? THere are many possibilities.
I suggest you look at the Colleges that Change Lives webaite. I also think you may have an interesting essay topic hidden here in your post.