Missing Media Files in MyBook Studio 1TB Harddrive


I’m missing some rather important media files on my MyBook Studio 1TB harddrive.  The Harddrive started performing incredibly slow about a month ago, so I went to Office works and bought a 2TB MyBook Harddrive to act as this harddrive’s backup.  In the middle of backing things up, I noticed some of the files would not copy to the new harddrive.  All of the files in my “Graduate School” file are missing - including the raw Final Cut files of last semester’s film project (which I finished about two months ago). 

Please help me figure out what I can do to restore these files.  That’s a lot of work, and I would hate to lose it.