Mate, if you are not getting through with nathan's help, time to take a break and do some self analysis.
Ring nathan and ask him, honestly, what HE thinks is holding you back.
Be prepared to listen, and accept what he says.
Then be prepared to go back, throw out all your thoughts about how good you are or how much study it will take, and concentrate on what Nathan said.
Then put off EVERYTHING in your life that could take some/any of your attention away from your primary objective, which is passing that exam.
Then do nothing for three weeks, except eat, sleep, study and do practice exams [maybe one or two walks on the sunshine coast beach is permitted!]. Do sixteen practice exams before you attempt the real thing. Not three. Not four. Sixteen.
Like everyone else is hinting at, it is not about being a genius. It is 5% inspiration, 95% perspiration.
Tune in to Nathan. Listen to what he says. Don't go looking for answers elsewhere. It is something YOU are doing/not doing.
Good luck
ITCZ