Reinstall of High Sierra went wrong

Hi all,

I own a macbook pro (late 2013 model top specs) and it has been working fine until recently. I usually do all my updates and don´t install all kinds of software on it. However lately whenever i turned it on from sleep, it didn´t boot properly. It started but then after i write my credentials for the log in process, it ran the status/ update bar then it died and i had to start it again pressing the power button and the same thing happened many times.

When I eventually signed in, after a while it shut down again. I decided to enter safe mode and erase the whole drive for a new installation of the OS. While i was installing it, it shut down again and now it shows the "prohibitive" sign.

Please help.

Thanks,

FD