Grades aren't everything. Most importantly, you'll learn this for yourself in time.
Put effort into your studies (which it sounds like you're doing), and make sure you dedicate time to things that aren't studies that interest you, that you are passionate for, and that will help you develop skills you'll be glad to have in the workforce.
Best way I can explain this, in an effort to alleviate some clear stress about your situation, is to give a few examples from my last few years in school:
I've never done great in school—not badly, but not great. Certainly not good enough to get into a school like University of Southern California on my grades alone. However, I took it upon myself to cultivate longstanding participation with a number of projects that I had a passion for, and developed a few enterprises of my own. Namely, 10+ years on and off stage in live theater. This has given me skills in communication, public speaking, and overall confidence that I never would have acquired from hitting the books and getting a 30 on the ACT. I produced and hosted my own radio show on a real station for over a year. This applied my passion for technology to a real industry that led to the best job I've ever had as a producer for Entercom communications. Also provided a great avenue for applying my theater skills through voice acting for the show.
Bottom line is, work hard in school—but work harder to understand what will personally benefit you most in the long run. For me, doing just well enough in school to supplement my numerous activities set me up to take my passions to a more professional level. Most importantly, all my activities carried a huge amount of longevity. I didn't just try theater once, I dedicated year after year to it. That's what makes the difference.
Don't stress too hard, and really don't let your parents get you down. You're (academically) doing a great job. Your efforts will pay off in time—even if it doesn't seem that way now. Keep up the great work, keep your standards high, and focus on better yourself FOR yourself. Not for your parents.
