holy shit holy shit cuz,
Are you serious, you fucked up I guess, you have HSC next month, go fucken study instead of crying bro!
Good luck in failing HSC chemistry.
Edit: I think you fall for my joke! Just work hard lol, you can't do more than that. My first tip would be, to find all the calculation quetsions from a range of textbooks and HSC papers, then do them all and mark you answer.