Forgive me if I don't fully understand but the drive that has died is the boot drive which contains the data and is what you are using to access single user mode correct?
If that is the case, see if you can get another computer to create a USB boot drive and connect that to your Mac and boot from it by holding the "Option" key ⌥ when the apple logo appears and selecting the drive (on new systems select "UEFI").
From there you can try some terminal commands to try and recover your data, or if you have an external drive handy you can install Mac onto it and boot from that. From there you have the entire Mac operating system to recover your data from the drive with a fully functioning disk utility with GUI obviously.
Hope this helps and good luck!