Invalid Node Structure

So, the other day I opened up my MBP 2011 (on El Cap) and found it to be drained. Plugged it in and booted it and got a folder with a question mark thrown in my face. It stood there for a while and flashed between the folder and the Apple logo. I thought the worst. But then it suddenly started to boot, hooray!

Figured I should backup and get a new disk, but ultimately I forgot about.

So today it came to a halt and I had to shut it down with the power button. It of course it won't boot anymore at all.

Single user is not possible.
I can use internet recovery to get to diskutil, but it fails the recovery with an "invalid node structure" and "disk full".

Same happens if I go to the terminal and run fsck_hfs -l or fsck_hfs -yprd. Volume was found corrupt and needs to be repaired.

So the disk is probably toast. Nearly 5 years old and never(!) formated. That's why I figured it was running so slow. I'm holding out for Skylake MBP's (Apple this is all your fault!).

Now, what's my best course of action here?
Get Disk Warrior and try that?
Try accessing the disk via target mode from another computer?
Use ddrescue (how do I do that?)

Any other alternative that would be better?

Any suggestion is appreciated!

Thanks

 

I'm running the disk through ddrescue now. It seems as if it's the cable that's broke, because when I mounted a new disk it would not show up in diskutil. The corrupted drive is in read only mode. Not sure if this is a good or bad scenario seeing as it's corrupted either way..

I do not have a backup sadly. And I don't need lectures about that at the moment, hehe.