Yeah me too. Everybody is my friend, but at the same time I'm competing against them for the ATAR. So how do you get past this apparant paradox? I still don't know 
You're doing it wrong
VCE isn't a race or competition per se. You're not going to get any advantage thinking that you'll do better if you're ahead of them. You're also not going to get any advantage if they do much worse than you. You're also not going to get much of an advantage to yourself if they are the ones that happen to be ahead of you at the moment.
You're all sitting the same exam, at the same time,
individually. They're not going to affect your performance in SACS that you sit by yourself, and they're not going to affect your performance in exams that you sit by yourself.
You might as well get along and work with your classmates, rather than thinking of them as serious competition (friendly competition is a different thing).
Paradox solved.