1)You did really well in your presentation-objective fact(your teacher told you that you got a high mark)
2)You are 'guessing' you 'failed' the test-subjective opinion
So based on the above unarguable premises, you might well have passed your exam and maybe even did much better in it than your post-exam pessimistic tendencies are leading you to think, I think you should based your judgment on objective facts rather than mix it with your subjective opinion, this is a way to maintain a positive psychological mindset for the HSC
Are my Band 6 chances over, is it too late for me to move up?
1)No-unless you think your performance of a part of an assessment will result in that
What I suggest you do:
1)Stop thinking about the exam and start revising for any other exams you have coming up, or reward yourself for doing well in the presentation, stop thinking about possibilities and confront the exam when you get actual exam results-when you will know whether your prediction is right and get comments on how you can improve
2)Your HSC score in any subject is a combination of your school rank, your cohort's performance and your performance in the HSC, if that ancient exam was hard, then no doubt other people will find it hard as well, just remember, this is a year long battle-you've just done one assessment, there are still 80% of internal school marks up for grabs, plenty of opportunities to redeem yourself even if you did 'bad'
3)Keep trying and keep studying and that band 6 will be waiting for you at the end of the year if you never stop believing that you can get there. Maintaining a positive attitude is an important part to succeeding in the HSC-not just for ancient history, but for all your other subjects, after one assessment, you don't know your overall mark and yet you are already questioning/doubting whether your band 6 chances are over seems a bit too melodramatic.
4)The question you should now be asking is 'How to make sure I can get a band 6 at the end of the year?'-and implement time management strategies that could allow you to have enough time to prepare for your assessments and study for them effectively