Marks are not real identity for good learning. Thorough learning is from how better you get to know the concepts. We need to get marks only to pass the gateway of getting better job after that concepts and subjects we learn really matters. So learn in depth with understanding and automatically you will score marks.

Don't loose your confidence level,get clear understanding with your subjects and make hints about that, do not mug up the concepts it won't help in exams.

Scoring marks in the examination is all about the thorough knowledge and the deeper understanding of the concepts.

You can try by getting up early in the morning and revise the subjects once. Then u can write and practice on the tuff subjects so that u wont forget the things. May be this will be useful for you to get better marks.