How to Deal With a Bad Grade
The best way to handle a bad grade is to look for a pattern behind your mistakes, like a certain subject you did poorly on or a style of question you struggled to answer correctly. Ask your teacher for more detailed feedback and ask your classmates for studying strategies that you might be able to try. Write out goals for improvement so you have them in mind, and avoid procrastination and distractions while you study.
Don’t be too hard on yourself. Receiving a bad grade isn't the end of the world. Don't think one bad grade represents your overall worth as a student. The very fact that you are concerned shows that you are motivated and have high expectations for yourself. Avoid punishing yourself for receiving a bad grade. Try to learn from your mistakes and strive to do better in the future. Remember that a “C” is usually considered average, a “B” above average, and an “A” exemplary. Putting it into perspective, maybe your grade isn't as bad as you thought. Take some time to process your reaction. You may feel anxious, frustrated, or even confused. It's okay to be upset. Let it out. Suppressing your emotions will only make you feel worse down the line. Venting to a friend, family member, or classmate can help you cope with the bad grade and move on. Put some distance between you and the grade for a while. Dwelling on it further while in a heightened emotional state will just make the problem seem worse than it is. Try to do something that takes your mind off of it. Exercising, talking with friends, listening to music, or doing fun things you enjoy are all healthy ways to relieve anxiety. Look for patterns of error. Finding a pattern in your mistakes is a good way to isolate and overcome your problem areas on your own. Was there a subject, like math or English, that you didn't do well on? If so, study more frequently in those areas. Was there a group of related test questions you missed? If so, try to categorize them and figure out what subject you could study harder in. Did you continually show up to class late? If so, try to be more punctual. Ask your teacher for detailed feedback. They know your strengths and weaknesses, so don't be afraid to ask for help. Instead of asking, “why did I get a bad grade,” ask, “how can I restructure my answers in a way that would earn me a better grade?” Seek advice from classmates. Ask others if they're willing to share the grade they received. If they all received similar grades, maybe the problem is with the material and not you. If they did better than you, ask them what kind of strategies they think led to higher grades. Sometimes teachers curve the grades in a class in which many students are struggling. If a lot of students did poorly, a low grade won't be as detrimental as you thought, and you can rest easier knowing that. Reflect on your study habits. Try to be fair and objective while you self-reflect. Take some time to think about how, and how much, you studied or prepared for the assignment. If you didn't study or if you procrastinated, this could have contributed to the bad grade. Aim to improve your study habits in the future if this was the case. Commit to your goals for improvement. Once you've recognized areas where you need to improve, you can take the steps to do so. Make positive changes in your life where necessary: Write out a study schedule and follow it routinely. Consider other activities and obligations you have and allow for plenty of time to complete each assignment. A regular schedule can significantly reduce anxiety and improve performance. Just be sure to avoid procrastination. Get more sleep. The amount of sleep you get heavily affects your mood and ability to absorb and retain information. Eliminate distractions. Prioritize the things that matter most. Seek extra credit opportunities to make up lost points. Oftentimes, teachers just want to see that you're willing to put effort into your work. Ask if they'd be willing to let you improve your grade by completing extra assignments. If you can't change your grade, maybe you can supplement it. It's a good idea to calculate your grade and figure out what scores you'll need on the remaining assignments and exams to achieve the final grade you desire in the course. Be mindful of helpful resources at your disposal. Tutoring centers, teacher office hours, and study groups all exist to help you succeed. Consider restructuring your future study habits by incorporating some of these resources into your routine. Move on. While you may not be able to change the grade you've received, you can take the necessary steps to improve. Try to consider it a learning experience. Forgive yourself for your mistakes, and focus on working hard so you do better next time. One bad grade isn't going to determine your future, and it isn't going to define your aptitude as a student either. 
Don’t be too hard on yourself. Take some time to process your reaction. Put some distance between you and the grade for a while. Look for patterns of error. Ask your teacher for detailed feedback. Seek advice from classmates. Reflect on your study habits. Commit to your goals for improvement. Seek extra credit opportunities to make up lost points. Be mindful of helpful resources at your disposal. Move on. 