Don’t be sad. You are taking on a big schedule. Be proud of your accomplishments. Focus less on grades. More on ensuring what you missed, especially in calc. It builds.
What you need is a school that will admit you and that you can afford. Top 20 - whatever that means - assures you nothing. Similarly, lower ranked schools don’t mean failure.
Look at some of the threads today from schools ranked well below 20. Kids with 4.0 and 1500 with rigor aren’t getting in.
At the same time, less than perfect kids
statistically do get in top schools too.
Control what you can - and that’s you. A GOA, test, essays, extra curriculars.
There will be many schools that will be lucky enough to have you.
Are you looking to do engineering ? If so, rank matters little. Kids from all sorts of schools get the same job.
You don’t need so much stress. Stop beating yourself up.
Good luck.