No not at all, just get the trevor thom book, make notes and really study that confuser!! The PPL air law knowledge is the foundation for most of what you need to know for the ATPL's. But if you find the PPL exams tough, wait till u get to the ATPL's - Nightmare, im doing them now!!
But as they say, hard work pays off so keep at it. Im guessing its the last 1 u need to pass??