Lost my data files and unable to recover
I am using Seagate 1TB external hard drive from past 2 years and copying the files/folders from my laptop to the external drive. I was clearly maintaining folders and use to copy the files regularly. Today when I have connected and opened it, I couldn't see any files in old folders. Looks like I lost all my data.
Is there any way to recover the data? How can I make sure this will not happen next time? Any help or suggestions will be very much appreciated. Thanks in advance for your help.