data recovery – Acessing encrypted /home/ from a live USB – mount passphrase problems

I saw lots of people with similar problems here, but no solution that works for me yet. So I updated my system (Ulyssa, xfce) after about a month or two of not booting the laptop with a poor wifi connection and some packets did not download, but I went ahead and tried to update anyway, the next day the laptop would not boot normally, got as far as to the login screen for a moment, but seems like the installation is corrupt. So now I booted up a liveOS Ulyssa xfce from USB, hoping to access my /home directory. I got as far as
sudo ecryptfs-recover-private /media/mint/109b295b-24c9-40de-9fd3-c8069cba2c2b/home/user but then I am asked for my MOUNT passphrase. As I understand this is what happens when the system can’t locate the encrypted MOUNT passphrase that I would be able to decrypt with the login/sudo password of the corrupted system. I remember the login, but don’t have the MOUNT passphrase, plus I am certain that I was not asked to write anything down when I was encrypting the drive when installing the system for the first time. I see three potential routes out of the situation:

a) maybe it is possible to somehow repair the installation of the system so that I can just log in normally?

b) maybe there is a way to find the file which holds the encrypted MOUNT passphrase? (sudo encryptfs-recover-private returns command not found)

c) some other way forward recovering the files on /home using only the login password?
Anyone?