First variant you may use if your .psd file was seriously damaged
https://www.repairtoolbox.com/photoshoprepair.html Photoshop Repair Toolbox
Second solutions are showed as knowledge bases about Adobe Photoshop
Open “My Computer.” In Windows XP, the icon is on the desktop. In Windows Vista or Windows 7, you must access this via the “Computer” option in the Start menu.
Double-click the “C” drive, followed by the “Windows” folder inside. Locate the temporary Photoshop folder, which will look similar to this: “Photoshop Temp6382948398.” Double-click the folder when you find it.
Locate the file inside the temporary folder that matches the name of the corrupted file. Double-click it to open it in Photoshop.
Click “Save As” in the “File” portion of the main menu bar. Save it in a different location and under a different name