Trouble with mac

Hi, i've been having some trouble with my mac book pro for the past couple of days. This all started when my mac was plugged on a faulty plug and keeps happening at random times since then.
I took it to a technician but after a quick service and a cleanup he couldn't find anything wrong with it. Its exam season, so this really needs to get resolved soon, and noone even seems to know whats wrong!

At random times my screen either freezes and turns grey, or stripy, or sometimes just splits in too but still shows what i was doing. I can fix this by force-restarting my laptop, but even while restarting the apple logo sometimes gets a strange pinkish hue or lines. It does this many times in a row.

Any idea of what is wrong or how i could even fix this?
(i've attached some photos from the last troubleshoot)


Your help would be much appreciated
Theo

 

Does that mean i need to change my GPU or is there a way to fix it without changing it?