So I decided to run an Erase Free Space operation in Disk Utility, and I let it run until it said "deleting free space" (went through creating the temporary file that takes up your hard drive space), but it said it was going to take 10 hours and I didn't want to wait that long, especially because it was making my system crawl. So I stopped it, and let it run though it's "skipping" process and restarted my MacBook. But now I only have 54GB available; before I had 64. Any advice? Did Disk Utility leave anything behind and if so where is it so I can get rid of it? Thanks!