I'm sorry you're feeling this way, but you must keep in mind that setbacks and self-doubt are frequent during the exam-preparation process. To boost your performance and regain your confidence:
Set attainable targets: To keep track of your progress, divide your study plan into manageable, smaller goals.
Review your approach: If your study techniques aren't working, evaluate them and think about changing them.
Don't be afraid to seek professors, classmates, or tutors for assistance with difficult subjects.
Maintain consistency: The key to improvement is consistent work over time. Maintain a consistent study regimen.
Take breaks: Include quick breaks in your study regimen to prevent burnout.
Stay upbeat by keeping your attention on your successes and reminding yourself of your potential.
Manage stress: To lower anxiety, use relaxation techniques and keep up a healthy lifestyle.
Never forget that it's normal to struggle occasionally because it's all a part of learning. Work diligently and you will advance.