FFP (1): I feel like there is a huge amount of information that I must absorb and learn.
-- You have to understand how your brain functions in order to organize how to carry on with your learning.
FFP (2): I can't find enough time to study all the subjects I have.
-- You might be overwhelming your brain with all the stuff you got to finish that you end up not finishing anything. This problem could be related to procrastination or time-management.
Check out how to stop Procrastination for more information about this problem and how to effectively manage your learning time.
FFP (3): I do very well on exams but I don't remember anything that I have learned a week after the exams.
-- You might be doing good on your exams but you are certainly not learning the subject. You should know How Your Brain Operates and how information is stored in your memory to be able to genuinely learn what you are trying to learn.
FFP (4): I am not good at maths. I find great difficulty in dealing with subjects involving maths and I give up.
-- Don't give up on maths! Practice makes perfect. Check out the Tips and Tricks for effective learning for some learning techniques to help you out change your state of mind about the difficult subject you are facing.