I wonder if things are not so dire. OP, you do realize that life exists outside T20/T30 (whatever that even means!), right? A student like you will have lots of great options when it comes to college, even if there’s an F on your transcript. It troubles me when students (and parents/posters) think of college admissions as a finish line (I must get into one of these schools because then I win!) instead of a starting line. Do the best you can. Pull up that grade or retake the next year. You’ll be fine. Oh, and the earth is littered with the bones of once hopeful pre-med students, so have other plans just in case. One pre-med friend of mine went to law school instead. Another went to dental school. And as @4gsmom stated, “Maybe you have to rethink what ‘top tier’ means and look at a ‘top tier for you.’” Wow, those words should be put in a permanent banner on this site.