Even I faced similar problem one day.
I deleted few files with "rm" command.
But Linux is very clever. It maintains backup files.
Just open terminal and go to the directory/folder where you kept the file/s using "cd" command.
Now list the content of that folder using "ls".
You will see the backup files as "xyz.txt~"
Open it and save.
Or if you cannot find any, try the procedure given here: