"Skipped" Erase Free Space, No Space On HD

[Rachel!]

So I managed to interrupt the computer when I selected the "Erase Free Space" option. I had 0GB left on the computer and had to cancel almost all of the applications. I Googled and found that /var/root/Library/Caches/TemporaryItems should locate the file when entered in Terminal, but whenever I try that, it just says "Permission denied." It only asked for a password once, and when I tried entering it, it said that there was no such file. I located a few other temporary files and deleted those, and also tried making empty folders on the desktop to empty the trash. It freed up 6.7 GB, but there's still a lot of space missing. I'm not sure what else to try or how to get the space back. Please help! Thank you.

 

[Rachel!]

Update: I downloaded OmniDiskSweeper to try to locate the larger files. I found a folder filled with files marked with 0s, so I figured that must be it. I deleted it, figuring it would solve the problem, and restarted. When I checked Disk Utility again, it said that there was still only 6.9GB available. When I checked the trash after restarting, there were two random files along with a folder named "Recovered Files". Inside was something marked with ETF or EFT or something like that, which I recognized from some other site, so I went ahead and emptied it. Space is back up to 195GB available. Phew! I was getting really worried, there! I'm still not 100% sure as to how that file wound up in the trash, but I'm glad it did!