What American colleges want is the schools you attended between the age of 14 and 18.
So, you would enter two schools: your secondary school, then your college ("sixth form college" is the British term for example, or "FE college", preparing for A-levels).
There are many cultures in which "college" means "non mandatory, upper-level secondary", especially those which British-patterned or -related educational systems. Enter both "Secondary school" for the 14-16 part and "college" for the 16-19 part.
Washington St Louis and Vanderbilt love high test scores, so they'd be worth a try.
No matter what, remember to start with 2 safeties you like, then add 3-5 matches. Once that's done, you can add as many reaches as you wish.
Also, do check with your parents that you have no financial restrictions (or other restrictions) indeed.
First, go to office hours and get a tutor TODAY.
Second: Is to too late to withdraw and take a W?
Third: CS to art sounds like a drastic change... What sort of art? Have you had success in that field before?
A First gen lower income student with a 30 act can aim for Yale @sybylla. And a premed with an A in all 4 premed classes including two killer weedout classes is outstanding; even if the final counts for 30% of the grade the student is still at the very top of the curve.
These are superb stats.
Grinnell would be a great possibility (better than Pitt actually). They are very generous to lower income students.
Email something like
"my name is.... and I am currently a freshman at Pitt, interested in the sciences. At the end of this semester I will have 15 credits; my GPA is ... As a .... High School student, I had a ...gpa and ... Act. I am very much interested in transferring to Grinnell but as an EFC zero, first gen student, I need to know, if I were lucky enough to get in, would I qualify for 100% need financial aid? Also, do you still accept applicarions for the spring* or would I take a gap semester and have apply for Fall2018?
Thank you very much.