you need to reduce the amount of supplementary texts. It almost seems like your fleeting over texts in a hurry when rather you can discuss them in greater detail, 3-4 is the average amount but markers also want to see a deeper involvment with the texts you employ rather than using all these texts to answer the question. The problem that many made before according to my teachers who have been marking 2u, 3u HSC papers discussed that total understanding of the text is better achieved when looking at detail.
e.g. when you looked at Margaret Atwood's poem "JTTI)
you listed the enjambment etc rather than showing it. Even one reference of it is fine, but you MUST AVOID LISTING also discuss her context. because i haven't read/wtached etc your other texts, i can't really say anything else. But i also had this question in my half yearly and used Atwood's "JTTI", "On first looking into chapman's homer" by Keats and i don't remember either if it was Dali's painting "the burning giraffe" or Rob Reiner's film "Stand By Me" but generally, you don't need alot of texts to support the idea. But overall, you have a good ability of picking out certain technniques in the summary of the text, but concentration on certain texts might be better (realistically as well)