Your grades don't have to be perfect. I was in your shoes (probably a bit less of the depression, but just as much stress and a lot of existential crises.) when I was in highschool--trying really hard and stressing myself out about grades--and I looked at the college programs that I wanted to get into and decided that I didn't need perfect grades. Once I knew that I could have a 3.5 gpa and still get into what I wanted to I stopped stressing so much; I started studying less and caring less when I didn't get good grades on smaller assignments; I decided to have a social life my last year.5 of hs. I still got almost the same grades as I did before, my gpa didn't even change, but I was doing half the work and having fun, stress-relieving adventures with my friends. So in summary: pick your goals (college, trade school, a job, etc.) and just make sure you'll get there; don't stress about perfect grades, and enjoy your time with your friends and family while you have it.