HELP me please!

I have a WD My Book Essential external hard drive and I was attempting to backup my files from my MacBook and had several problems that led to a major problem.

First I was wanting to backup a specific folder; BUT after reading the manual, I found out this is impossible.

Then I decided that I’d just back up the entirety of the computer, when I hit the backup button it took 1 minute to say it was complete and then all of the blue items from my Macbook were gone, however it said that my external hard drive also had 0 items on it. 

So I ejected the WD hard drive and tried to start from scratch, but it still said there were no files to read on my computer.

So I ejected the WD hard drive again and restarted my computer.

Upon restart all of my things were gone as if I had master reset my computer.

WHERE ARE MY FILES!?!?!

PLEASE HELP ME! 

you have some sort of virus or corruption in the drive and the Mac

We recommend scanning the drive and computer with a antivirus

you can use a data recovery software to retrieve the files