That being the case what you need to do is review your time allocation and make sure that you are spending your precious time simply focusing on the needs of the revised task. All efforts should be spend doing the following:
Read through your class notes and articles that you have amassed.
Actively make notes from these in meaningful ways. This will vary from student to student.
Summarise these notes into themes and ideas. Perhaps a page per idea.
Design a 'table' summary page that has all of the ideas, quotes and techniques on one page.
Open Book Exam
Many schools are permitting you to have notes in the exam. Mainly because online they cannot police this, so it creates an event playing field.
This means that you are actually being assessed on your ability to organise your notes meaningfully and this will prepare you for the actual HSC.
After preparing your notes you should practice with sight unseen essay responses. You need to guard against 'dumping' a previous response into a question that is asking for something else. This will simply tell the examiner 'everything you don't know about the text.' That means it is telling them that you can rote learn your understanding of the text but do not know it well enough to be able to interpret the question for the knowledge that you have.
Do numerous responses
Get someone reliable to read and criticise.
Use your notes as little as possible (the more practise the less you will rely on notes, the more you will write in the time allocated.
Make sure you write a full response with Intro/Body and conclusion.
When the task and your 'trials' are over for all tasks, make sure you prepare all of your responses in this way for the actual HSC. Don't leave this until the last minute.