Severe performance issues on web browsers

Sundr0wn · May 22, 2018

I just recently built a decent Ryzen 5 system and i've been noticing some severe performance issues on my web browser (chrome usually, altough switching to edge or firefox made no difference). Everything else is running fine, but video playback is laggy, scrolling is too, pages load forever and the browser ocasionally freezes. Until this morning where all browsers just keept crashing on me. Turning off Hardware acceleration in chrome didnt help. And then i found the video below, the final step in it seemed to finally have fixed it, but now barely 8 hours later, the performance is already dropping again. Task manager looks normal too (i have 16gb of ram so that wont be the issue), except that the Ethernet keeps spiking up and down, but i dont know if that's just normal when it tries to access data. I thought maybe the wall plug cable (antenna?) on my modem was bad since i've had it for a while and just replaced all ethernet cables, but all other devices work fine. My connection is also a good one, i dont have like "shitty internet".
I use Avast premier antivirus, could that be it? Sounds far fetched for such severe issues to me.

Any help would be greatly appreciated since it is very annoying and it made me start my stream half an hour late today, which is really not good.