Hi, lapinus
i'll try explain just a little bit better
I believe that you are using the latest combo 10.11.6, ok? If not, please install last combo (10.11.6). Why this? Because you said that you do not have good knowledge to edit system files. And.. so we are sure that the system is ok.
After, please, boot into Recovery Mode. How? Simple:
1 Reboot your Mac into Recovery Mode by restarting your computer and holding down Command+R until the Apple logo appears on your screen.
2 Click Utilities > Terminal.
3 In the Terminal window, type in: csrutil disable and press Enter.
4 Restart your Mac.
Ok, now you are into OSX again.
Please, if possible, search and download a app called: Kext Drop. (this is not marketing, okay?) Only to facilitate the process.
Download my AppleGraphicsPowerManagement.kext (already edited) here:
https://dl.dropboxusercontent.com/u/35721057/AppleGraphicsPowerManagement.kext.zip
Open Kext Drop and drag .kext inside. Press install.
Attention, this .kext only works if the system is upgraded to 10.11.6.
(But the “hack” manual in .plist can be done in other versions of OSX)
Reboot.
To check, open Console app (type in the spotlight), and search for: GFX0
Like this:
https://dl.dropboxusercontent.com/u/35721057/console.png
Test if this ok and free GPU Panic.
(Edited)
AppleGraphicsPowerManagement.kext 10.12
https://dl.dropboxusercontent.com/u/35721057/10.12.AppleGraphicsPowerManagement.kext.zip