If you want to overcome the difficulties in leaning English gramma, you can set up your mind to get rid of it. I remember one of my English teachers has said: Gramma is rubbish" o(∩_∩)o
BUT you need to pass the exam. So I strongly advise you to break up the whole into parts. You can learn them bit by bit. You can buy a small, portative grammar book to do your study. Making a detailed plan may be of a lot help.
Don't be afraid of them. When you bite them off, you will find indeed the gramma is not so hard to deal with.
Good luck !