Game-ruining map VGU glitch + FPS drop

https://imgur.com/a/y3j2eU8 (Video link)

Ever since I installed LoL I've been having this weird bug where the map's VGU starts going up in a straight global line if that makes sense and creates these glitches above that's mostly visible when I'm dead. Usually it's pretty minor but now it's much larger, noticeable and has been screwing my FPS where 20fps is the max and sometimes it'll just be stuck at 01 for 5-10 seconds, this glitch popped out of nowhere and I haven't downloaded anything and cleared all malwares. I don't really know what details would be useful but I'm using AMD Radeon R5.