Worried about college acceptance

Hey there I’m currently a junior in high school and I’m suddenly worried about acceptance into my first choice major at UT Austin. I’m an auto admit currently since I’m in the top 3% of my class currently but I just feel very insecure about getting into the major I want. My SAT scores were not near where I hoped they would be so I think I’m gonna take the ACT, I have very little leadership shown as I’ve only been an officer for colorguard this year, I’m only in 3 ECs and I dont have a lot of volunteer experience (which I plan to change this summer but I’m not sure will be good enough) and I’m just not confident about my abilities to get in at all. I dont think I stand out enough, I’m just ordinary.

I’ve just been really disheartened recently because it is my dream to get into my first choice major at UT and it feels impossible, it feels too late to fix everything I’ve done wrong. And advice?