Hi. Exam pressure and fear of failure are not two good combination for a good focus and concentration. It is natural for a person to question their ability after a failure. It is difficult to focus on things which they have done over and over again. I would suggest you to see a counselor and discuss in depth about yourself and he or she will be better able to guide you in the matter. Don't lose hope or feel guilty that you are not studying when you are suppose to. It will not help you to study at all. Hope this helps.