I remember this exact same feeling. I am in college now, but I will never forget the time right before my first day of high school. I will not try to convince you not to be stressed because believe me, I know how you feel, but what I will say is even a few months from now (if not a few weeks) your first day will be a very minor, forgettable experience. Soon you will finish up your freshman year, then-sophomore, then high school is over, and you’re off to your next thing. It goes by fast. Your pain and anxiety you feel now will be gone before you know it. It will feel like a distant, painless memory.