Your data is still on the disk and you should be able to get it all back.
Download Recover My Files from
www.recovermyfiles.com. Start by running a "Fast Format Recover", and in the drive selection window select and search the "physical drive".
If the Fast Format Recover does not work, next try a "Complete Format Recover" of the physical drive and search only for the default selected file types. This will be a longer search.
At the end of both searches, look in Folder View of the results screen for your files. Click on them to preview their content, and then if you can see them, you can activate the program and save them to your C: drive.
Dont write any data to the problem disk until you have recovered everything (writing data to the problem disk will overwrite and destroy the lost data).
Please let us know how it goes.
Thank you.