What the fuck just happened to my game?

I have a expensive monster gaming pc which is all up-to-date.

Always playing smooth, perfect, on the highest settings. Never have any problems.

Today I was playing Ranked and 5 mins in, the screen started to stutter like crazy so I had to restart.

Two mins after restart, i got this message: https://i.imgur.com/iPbokaI.png my Internet connection was fine, no problems.

I tried to reconnect it didn't work. So I jumped to the monster pc next to me who is from my partner, so I could continue playing.

To be safe, I lowered the settings to prevent shit from happening.

After 5 mins This error occured:

https://i.imgur.com/H5gQjxy.jpg

In the middle of a teamfight.

I tried to restart client and this error popped up every 4-5 MINUTES! So the client completely broke down every few minutes...

What the hell ? my game got totally ruined and my teammate flamed me for keep going AFK while I could do nothing about this