SOS! Had big trouble when upgrading to High Sierra…

[assdert]

This was what happened.

My 2010 mid Mbp had a fusion drive 1TB, and had latest Sierra installed.

I tried to upgraded it to High Sierra 10.13.1 at App Store. But it stucked when showing a progress bar never move..., so I pressed power to force restart. And I got the endless error screen repeating...
So I tried command+R to re-install High Sierra. This time it gave me the Prohibitory symbol screen...
Even I tried First Aid, it said there was no problem of my fusion drive.

Yap...I didn’t had backup, that why I am so scared to loss all my data...

Any one can help me get out of this situation? Please!

 

[Mac Hammer Fan]

If I were you, I would boot with an external disk where Sierra is installed and copy all the important files to it. If necessary, ask a bootable disk from someone else. High Sierra is slow on a fusion drive and especially on a 5400 rpm hard drive.

 

[Fishrrman]

OP:

If you're still there, have you made any progress?