i get that, and yeah you're right, school is a training ground for the workplace
It's also the place where you get molded to fit with civilized society, just like everyone else (i.e. it's not training just for the workplace). Year 12 is a culmination of the habits you've developed over the years in primary and secondary school. It's going to be hard to make major lifestyle changes since you're right in thick of it now, but if you feel like shit is really hitting the fan, then you should consider making some drastic changes to improve your environment and seeking help from your school counselor or equivalent who might direct you to additional resources (I get the sense that's not the case, though).
But more than ATAR, I think that school itself becomes a bit of a footnote later in life: something that you might remember with some fondness, or prefer to forget, but not the be-all-and-end-all it may have seemed at the time. With insight and effort, you still have the opportunity to develop sustainable habits.
but i think you misunderstand. my question is when will I live? or when will i stop yearning to live? the workplace isnt life.
Work is part of life as we know it. What is meant by "workplace" is has evolved over the years, but ultimately, we are made to understand that to flourish in "civilized" society, you have to earn to making a living, and in order to earn, someone has to be willing to pay you for it. You then have to decide if it's worth your time, or to move on. There's pragmatism in working a well-paying job that you loathe if you can live well and have decent work-life balance, but to last long at that job, those rewards obviously have to somehow more than offset the stress you bring from work. There's also something to be said for enjoying your work and living a more modest--but nevertheless enjoyable--life. You just have to figure out where that sweet spot is with the opportunities you have at the time.
In the same vein, don't forget to reward yourself after study. Make sure that you keep up with your photography and web development after HSC. Plan to work part-time to develop some financial freedom. Learn how to balance them with your coursework. Knowing there's something afterwards will help.
also, i can't build interpersonal skills if ive thrown away most of my friendships because studying for an exam or doing an assignment always takes priority
The opportunity to develop inter-personal relationships is always there. The first immediate one really is how you deal with your parents' expectations as that seems to be a sticking point. That dynamic is going to constantly evolve, and they are probably going to be figuring that one out themselves. The second one is how you deal with your friends. Friends and acquaintances come from anywhere--school, university/TAFE and even work. I mean, right now you have a bunch of like-minded people in the same boat as you and you're commiserating with some of them on a forum.
I know you are just destressing through forum-posting because its crunch time (totally valid strategy, by the way), but there's not really a single definition for "living" or a formula for when and how it happens. Get out of your comfort zone, be open to opportunities, travel, meet people, learn something new, but don't be a shooting star. Life's a marathon: pace yourself, set aside some time to manage stress (hang out with friends, work on your hobbies, whatever) and do your best with your ATAR. Doing better just gives you more immediate options, but there are usually ways to get in to do what you want to do if you don't make it on the first try--just expect it to take a bit longer. There's always the pressure to strive further, even after school and it's easy to get dragged further into the rat race than you would like. Periodically taking time to re-evaluate where you are as you are now doing is helpful, but avoid comparing yourself to your peers too often--there's always someone doing "better" than you (and there's always someone doing "worse"). Much like what you are doing now, you have to find your own way of working efficiently and developing yourself without burning out.