Phillips External Hard Drive - Files have corrupted?

I use a Cyclone to transfer my movies on my Phillips external hard drive to my T.V so I can watch them through my T.V. On my hard drive I had about 200 movies, 500 songs and a load of pictures/backed up chat logs, etc. I have used my Cyclone a lot for this and I just plugged it in and it said formatting hard drive, I quickly turned everything off and checked my hard drive and now everything's gone and there are only three unreadable files on the hard drive titled in funny symbols and lettering. Is there any way I can fix this problem myself and/or get the lost files back?