MacBook Pro 15 doesn‘ boot completely

Hello!

After my Macbook worked for years without any trouble, I now have a problem:

I closed the Mac the other day without updating or installing anything, so that's not the problem.

When I start the Mac now, either the Apple logo appears and the loading bar runs halfway through and then the device shuts down.

Or the Mac loads until the password is entered and when I enter the password, the loading bar only loads up to about 80%. After that the device shuts down again.

SMC and NVRAM resets have been performed countless times, also without success.

Yesterday I started an online recovery by pressing the D-key, which did nothing, except that the Mac showed me for 16 hours that the "recovery" was being prepared. I then turned it off again.

So now I almost don't know what to do. Does anyone here have any other ideas?

P.S.: see screenshot for model information

[Image Edited by Moderator to Remove Personal Information]