If the file does not load in either Gimp or Krita then probably gone for good.
Since you are using linux you probably have ImageMagick already installed. As an act of desperation try in a terminal (where the file is)
identify -verbose filename.psd
That might get a "not recognized report" or with luck a very long listing of the file properties. example:
https://i.imgur.com/pHySMxd.jpgIt then
might be possible to extract layers using
convert filename.psd[x] somename.png
where x is the layer number. example:
https://i.imgur.com/QCg0q4q.jpgYou have to be careful saving/exporting large files in Gimp. The save/export dialogue closes but the file is still writing to disk. Close the image/gimp and file is corrupt.