Mac wont boot after successful High Sierra install

Hey,

I've recently successfully updated my MacBook Pro (2012) from Sierra to High Sierra and was actually bug free for most of it now. Until yesterday, alas.

I don't remember having any trouble when I shut it down last time but it won't boot anymore now. The progress bar runs toward the middle as usual but then stops and continues so slowly you barely see ist. After around 10 minutes it reaches the end and the bar ist completely black but nothing changes from then on. I let him give it a try over night but nothing again.

So I tried:

-Safe Boot

-First Aid in Disk Utility in Recovery Mode

-Single User Mode: fsck -fy

-Reset NVRAM

-Reset SMC

-Re-Install High Sierra in Recovery Mode (where the time had to be adjusted because of "The recovery server could not be contacted")

-Safe Boot with Verbose Mode (it said "Process[1xx] crashed: opendirectoryd. Too many corpses being created" before and after re-install-attempt and goes on infinitely)

nothing worked. The next step would be to use the Time Maschine but being the idiot I am, the last backup was 2 months ago. I'd love to avoid losing that data.

Has anyone else encountered that problem? From what I read, at least one of these methods did the trick for other people or they were smarter and used their Time Machine more responsibly.

Thanks for your answer!

lilninja9