I'm a self-taught student studying in Xi'an. Recently, I have been feeling stressed about my studies. Self-taught students must pass all the exams if they want to enter college and get a university diploma. If I pass two more courses, I will get the diploma. But failing one course three times has hindered me from achieving my goal. I don't want to give up. But I can't concentrate enough to study. Please tell me what I should do.