If those are the exact commands you typed in then you've deleted all your files because of a typo.
The actual command should have been
rm -rf ~/.gconf/apps/panel
Because you put an extra space after the ~ then instead of deleting the directory ~/.gconf/apps/panel you told rm to delete the directories ~ and /.gconf/apps/panel
rm -rf ~ /.gconf/apps/panel
/.gconf/apps/panel doesn't exist so it wouldn't have been deleted, but ~ is a shortcut for your home directory so you've deleted it completely.
If you need to try and recover anything then stop using the drive straight away, the more you use it the more you will write over your old files.
Searching the forums for testdisk or photorec should find you some threads outlining how to recover your data.