Every exam is hard (in the view of an erudite and hardworking student competing among his peers with similar mental faculties, not in the view of a student with abnormalities or special needs).
I hardly see an exam which can be easily tackled, and likewise, it wouldn't be so easy that the majority of the candidates can score full marks. Examiners have been staying quite coy about their motives and plans, and we wouldn't know which questions would appear. There is no other avenue to gain 100% confidence than to study the whole textbook and to revise our past exam papers. This task seems soporific, but it will definitely reap a lot of benefits.
Mastering new subjects such as calculus takes a lot of time and patience. It will never be easy, nor will it be too demanding. With a positive mindset, I can learn anything.