I recommend doing exercises from Kate Grenville's 'Writing from Start to Finish' .
Honestly, tell your teacher to gtfo, Term 4 should be all about trial and error, messing about with writing styles, doing character profiles and readings of short stories. After doing this, you will be able to see what kind of material you consistently produce and what you find yourself writing about.
Then over these summer holidays work on your first draft, then periodically revise the draft every week until submission. This is what my teacher told us to do and her cohorts consistently get into the top bands - because in the reflection statement (which actually makes up a huge component of the work, enough to separate an E3 from an E4), you can talk about reading Kate Grenville, your trials and errors, what you discovered about yourself, how you went about planning your major work etc etc.
As my teacher said: "Markers will eat that shit up." and they do, they really do.