hi! i'm in the same boat and i'm 100% certain there are other ppl out there who feel the same. like rn im insanely procrastinating doing my modern syllabus notes lol. compared to last term, my grind was insane and now i just feel like i've run out of steam.
i've talked to my family a lot about being concerned abt my future and they always say (which i think is pretty helpful so i'll relay it to you) is that we're all young and have a loooooong time ahead of us i.e. there is no reason to be worried abt having no idea what to do in the future. it's actually pretty common in uni for people to switch degrees, and my parents have told stories abt old coworkers who have dedicated their entire life to one single career path and suddenly changing their entire trajectory. for example, i've heard about this one lady who did a phd in some area of microbiology and then realised she had another passion and became a ceramic artist! basically what i'm trying to say is that you shouldn't feel dejected for not knowing what to do after high school, and it is completely normal how you feel rn.
another thing i want to say is that it is easy to feel like you're falling behind especially with the crazy grind culture that the hsc inherently encourages and how every study acc on insta projects their 12 hour lock ins. in my period of what seemed like burnout earlier this term, i realised i shouldn't beat myself up about not studying 5+ hours a day and instead do things at my own pace. i spaced out my study times, set a todo list everyday and took walks outside every now and then (it's really good to spend time in nature). i also didn't get mad at myself if i didn't complete everything on my todo list, i would instead reschedule those tasks and simply move on. slowly getting back into the routine of studying is the best way, don't immediately jump into it.
also, this may seem hypocritical as i am currently on this site, but during my time of burnout i stayed away from any content that was related to the hsc (unless it was helpful, most times not) bc it just further inflamed this fear that i was falling behind. now, whenever i see a vid of someone showing off their 12hr ypt session i just scroll past and remind myself i should do things that suit me and my own pace.
lots of talk i know, but just keep in mind u r not alone. i hope this helped in some way!