The files were saved in my laptop's SSD drive, under the 'Downloads' folder. I was deleting some other files within the Downloads folder without realising that I had also ticked the above-mentioned 'University' sub-folder.
When I pressed the 'Delete' button on my keyboard, a pop up appeared saying something along the lines of: "This file is too big to recycle. Do you want to permanently delete it?" Again, without realising that I had included the 'University' sub-folder in the list of things to delete, I clicked 'Yes' without a second thought.
I read through a few articles regarding data recovery but most of the methods do not apply to me - I didn't have File History turned on, nor Backup and Restore. The only possible solution left was to use data recovery software like Recurva, which did scan and find all but one folder within the 'University' folder (but I think that's because the file path was too long so couldn't be scanned), but everything was corrupted by the time Recurva completed the recovery process (which was only 4 hours after deleting the files and laptop not shut down yet).