Why will I be laughed at if I don't get into graduate school, and will be discriminated against and laughed at by others?

That's because you met a bad person, or you entered such a group of people. Just jump out. Birds of a feather flock together, and with what kind of people, you will become what kind of person in the future. These people, don't contact again, it's not worth your nostalgia. Everyone has studied for more than ten years, and some people have been admitted to graduate schools. If you don't do well in the exam, you will definitely feel that you didn't go to school well and learned nothing. After more than ten years, others won't care how good you are inside.