Hey again Ashley!
Thanks for the info! At this point, I think it's definitely going to be either the hard drive needs to be replaced or the console needs to be repaired.
Fortunately, there's a test we can perform to determine which of those is the case. If you can, try using your hard drive in another console of the same type (if you're using an Xbox 360S console, use a friend/family member's Xbox 360S console to test your console, etc).
If the hard drive works:
It looks like you'll need to send your console in for an official repair.
If the hard drive doesn't work:
It looks like you'll need to purchase a new hard drive.
Let us know how that goes and we'll work with you from there! ^_^