failed first AS chem test

i've just started year 12, and we recently just had our first end of unit test. i revised for the test and felt pretty confident going in, but there were GCSE questions I wasn't expecting as well as difficult maths questions that required a high level of problem solving, and in the end I ended up with a D. not only did I do bad, but I also got one of the lowest scores in my whole class, most classmates getting Cs and Bs. the teacher kind of implied that people who did badly should consider dropping the subject. i feel really embarrassed and disheartened after this, i want to tell myself that it's just a small test and i can keep practicing to improve, but with the combination of everyone else doing better than me and the teacher advising us to think about dropping it i don't know how to feel. advice?