Hello!
I did not study Chinese but a LOTE and I know that the study designs of language subjects are similar. (But that language is my first language so take it with a grain of salt.)
If you do want to continue with Chinese Second Language(I am assuming you are finishing year 11), I suggest language immersion. Nothing beats reading, writing and speaking in Chinese when it comes to improvement.
Also, go through VCAA exams and reports to have an idea of what level of language comprehension is needed for you and the exact structures and topics of the exams.
Take your time while deciding, you can still drop a subject after holidays if things become too difficult and unmanageable.
I hope this helps!