don't worry mate.
the ground school is one tough and ofter boring slog. You will often wonder why you are learning about things that you will never need to know again, and the fact is most of the work is in your short term memory and you will forget it.
Personally speaking it helps if you have a technical background but not essential. As you have probably been told its the amount of work which is hard to get over....its all about time management.
Feedback also saved my ass.
some exams almost 80% feedback. I suggest you come to oxford for a brush up course and try and get your hands on some feedback.
keep your pecker up.
The WISE alderman.