imac does not finish to restart because of opendirectoryd is crashing

Hi,

My 2011 Imac was recently updated to High Sierra a couple of days ago and every thing was fine.

But since last week, it fails to start.

I ve followed the procedure to test the hard disk, the memory, reset the vram, tried to reinstall high sierra from recovery mode and even from internet but it is still not working.

When I am in single user mode, I can see opendirectoryd is crashing because of segmentation fault and launchctl restarts it again and again.

I've tried to deactivate it but is does not seem to do anything.

I have no time machine backup so i don't want to wipe out the disk.

Does someone have any idea to help me.