Unplugged Monitor -> Windows + Games are since somewhat "laggy"

The title is somewhat wrong or misleading as I cannot explain it this short.

Basically, I had just reinstalled Windows 10 Pro for the third time after having had issues with first my massive sound setup drivers (they need to be in a specific order, etc), and then had issues with UltraUXThemePatcher, then VeraCrypt, etc etc.
I finally now have Windows running without any actual issues that I couldn't resolve myself. However, I by accident Unplugged my TARGA16 1080p TV (Monitor) while I had Discord and KakaoTalk running on it (during a Video Chat), and since then Windows and my Games behave weirdly laggy, however it isn't really lag as much as it looks like jitter/stutter/rubberbanding/hanging. It isn't that my FPS is really that much lower, but when for example I switch between my Multi-Desktop Environment with CTRL+Windows+Left/Right, then it looks like it hangs for less than even a millisecond, it isn't really noticeable in that Environment, however, I notice it when i play Call of Duty: Infinite Warfare or the likes. My FPS went from 60 to 54 for some reason, goes up sometimes to 60 but never down, and fluctuates between this 54-60 "limit". Not just that, but when I walk around, I notice that about every 2-3 seconds I get Microstutter/hanging, almost like SLI was back in the days, however I do only have a single GTX 1080.

I tried fixing this by first normally reinstalling my NVIDIA Driver, and when that didn't help I used DDU, but even that didn't help at all. I then last but not least installed the latest NVIDIA Driver that was just released, but it also made no difference.

So I ask you my smarter alter-ego's, what could be causing this? I have no CPU/GPU "overload" because I checked for that first, and like I said it also stutters/hangs even in the normal Desktop Environment, not just Games, and my PC shouldn't lag while using a normal Desktop Environment. So to be honest, at this point I am out of ideas, but I really want to avoid reinstalling Windows 10 AGAIN, because I always have to re-encrypt my main SSD and it does take a little while (but is definitely faster than with HDD's my every means).

Regards, your not so smart noob, -Loke

To add to the confusion: NOTHING, absolutely nothing has changed, it literally happened when I unplugged that Monitor, my GPU is Overclocked as it always is, same with the CPU, I am running the same programs as always, I even suspected Discord and KakaoTalk to be the culprit which is why I completely killed them off, but nothing, no difference at all.

Boop

Solved: The issue was the somewhat "broken" HDMI Cable. It partially broke when I turned/flipped the Monitor (which Unplugged it), and as such one or two of the Pins weren't in place, there was still a picture on the screen, but it bugged out my PC. I noticed this because I just wanted to try and switch out the Cable to see what happens, and apparently, that was the issue.