It might be that the classes are too hard for but maybe not. I’ll share some of my personal experience with you, maybe it will help you. In high school, I was one of the people in your classes you describe. I took hard classes, excelled in them, worked part time, had friends, and did competitive dance. It all came easy to me. I was in the top 10% of my high school class. I volunteered in clubs. But when I went to college (currently a freshman) it was a whole different experience. No longer was I on top, but everyone was on my level or better. I took anatomy and phys my first semester and got a 79. Granted college is harder but a 79 was totally unlike me. I vowed to get above an 85 on the next test, hoping for over a 90. I “studied”, stopped going out with friends and spent all my time on bio. All of this to get a 61 on the test. I was devastated. The other people in my class were going out getting drunk every weekend, hanging out with friends all the time and still scored 20 points higher than me. So I totally get how you’re feeling. The first thing I did was meet with my professor and talk to her about what she thought I was doing wrong and how I could improve. That was really helpful so I recommend meeting with your teachers. It can be hard but truly they want nothing more than to see you improve. It was hard for me to swallow my pride and ask for help but I did. Second, improve your study strategies. Again, your teachers can help with this. What I now do is review my notes after every class, if shes talking about something during lecture that I don’t get it, I go and see her to have her explain it better to me. I downloaded a flashcard app on my phone. I make a study guide before every test and email it to myself so I can read it on my phone where ever I am. The third test I took I got an 85 on. From a 61. I also didn’t spend every waking moment studying. If I wanted to watch Netflix I did that. I made sure I went to the gym and hung out with friends. I went out at night and studied in the afternoon. Restricting yourself so much doesn’t give you a break. Give yourself time to let loose, whether that’s through video games, going out to the movies, whatever you enjoy.Grades are not everything. They matter but when it comes time to apply to colleges, they want to see what clubs, activities, sports you were in. If you had a job. They don’t just look at GPA and SAT/ACT. Also don’t compare yourself to others. I was always really competitive with everything, including grades, but it did nothing but stress me out even more. So meet with your teachers, try to stay calm, get involved in other things besides just studying, and most of all give yourself a break.