Grades are irrelevant. The only purpose of grades is to gauge how well a student has absorbed instruction and is able to regurgitate it.
What matters about education — the only thing that matters —is what you as a student learn. That's only something that you can do yourself — teachers and tutors and the like can only help guide you to learning, but they cannot do it for you.
The emphasis others put on grades is shallow and unhelpful, especially for you, because it sounds like you are having trouble regurgitating instruction presented in the proscribed manner. It may be that you need a different learning paradigm in order to be able to internalize the subject.
Don't base your self worth on an arbitrary score like grades. Don't allow the opinions of others to form your sense of self worth. You are a person. You are valuable. You will figure out a way to guide yourself through and learn what you need.
