Macbook 12 2015 display issues

So basically just got this one a month ago, second hand, had no issues until 2 days ago when it started going nuts. Initially it could be solved with a reset, adjusting the brightness. now it only works 5-10 mins, have to do a SMC reset or NVRAM... is this the display? is it something else? it also does this in safe mode... what can i do, any solutions? is this the famous burn in instance, or smth like this? on some occasions the image starts fading from the corners into the center (like a night shift mode is on, but going to the point of complete dark screen).
help, please?
thanks

image: https://ibb.co/TMs4fMY

 

L.e. Apparently the issue is gone in safe mode, i would use it like this for the rest of its life, but it’s moving in slo-mo... any suggestions? Could it be a software issue? Should i reinstall the os?

 

no issues when closing the lid, whenever the issue starts up the laptop is untouched for several minutes...
no means of accessing an external display at the moment, i`m travelling till the end of the month, will try then... much appreciated for your response, any other ideas? thanks!