So I copied my dev_flash folder to a USB, plugged the USB into my PS3, installed the USB Firm Loader pkg, and ran it.
My PS3 began to reboot, and it said connect a controller with a USB cable, so I did. The controllers wouldn't sync, so I pressed and held the reset button until my PS3 would turn off. Then I turned it back on without anything in the USB ports, and it gives me the same message, but this time, my controllers will sync.
Now it displays the message that my PS3's firmware cannot be ran, and I must insert a USB with firmware 3.41 or newer on it.
What can I do to fix this problem? Obviously the CFW loader is not working.
And it looks like your hard drive / FW got corrupted so you'd need to download 3.41 to your PC and put it into USB Flash drive in the folder like this: X:/PS3/UPDATE/UPDATE.PUB and let PS3 to reinstall it. Worst case scenario is though that your whole internal hard drive would be reformated and all your data on it lost. (Just a mild reminder of importance of the backups, especially if somebody is tinkering with their system like this)