all my action disappeared

[#1]

After PS crashed the entire Action menu has been deleted
And there's nothing in the action folder

[#2]

After PS crashed the entire Action menu has been deleted
And there's nothing in the action folder

[#3]

If the Action sets (folders) were saved from the Action panel menu, they can now be loaded from the panel menu. If the set was never saved, they are gone.

~ Jane

[#4]

use system backup: restore points in windows or time machine in macos

[#5]

Using a restore point may backup you Photoshop references in time if it does not you may be able to get your user ID old Photoshop if backup users Application data.  They are in your user ID Photoshop preferences in a file named  "Actions Palette.psp" On windows my path is

"C:\Users\(your User ID)\AppData\Roaming\Adobe\Adobe Photoshop 2020\Adobe Photoshop 2020 Settings\Actions Palette.psp"

[#6]

More here, however, I don't hold much hope... You just have to live and learn in this case:

https://prepression.blogspot.com/2017/01/photoshop-custom-action-file-backup.html