100% relate to this. I was very similar and remember beating myself up about my lack of drive and motivation in Year 12. I ended up completely burning out and developing some unhealthy coping skills. I am now 25 and have graduated with an awesome degree and great grades, and can truly say it is not really worth stressing yourself out. Just work through it bit by bit, do what you can, and let go of the rest. Trust also in those who love you. I wish I had opened up a bit more about just how much emotional pain I was going through.