How screwed over am I from going to a competitive high school

Congratulations on having strong marks in a rigorous curriculum in a competitive high school.

Your marks will qualify you for any college. When you have test scores you will know whether they do as well. But: those are necessary but not sufficient elements of your application.

So, what are you doing with the time you are not in class or studying? The people who get into the super selective schools typically have high gpa + high test scores AND…

…it is the AND that you need to answer. It could be an EC or outside of school activity that you love, have shown a long and deep commitment to, and leadership in, and can talk about in an interesting way. It could that your summers are spent scooping ice cream to save money for college, or babysitting for your siblings b/c daycare is too expensive for your family. It could be…anything in which you have invested a lot of yourself. But the top schools are very clear: they want to know what else you do with your time beyond the classroom.