Need help salvaging what I can from major disaster

[Kynn Jones <kynnjo@gmail.com>]

The plan was:

  1. back up my hard drive to a new external drive;
  2. reinstall Debian;
  3. restore my data from the external drive;

I did 1 and 2, but when I went to restore data from the backup, there
was nothing there (except for a lost+found).

I don't understand how this could have happened.  I've done this sort
of thing many times, and this has never happened before.  (Needless to
say, I'm ready to shoot myself.)

Now my most pressing need is to salvage whatever I can from the hard disk.

Any advice/recommendations would be much appreciated.

kj