I don’t think your school has access to your results. Once they’re deleted, they’re gone forever and schools don’t know who gets what on the HSC. And regarding Google docs, you cannot retrieve any information. My school warns everybody a year in advance about Google accounts being deleted but I started moving any important docs and accounts tied to my school email over to a different email when I started year 7 so I could make sure I was on the safe side.
maybe try reaching out to nesa, think there is a point where you can buy back some of the data!