Weird performance issues.

[Aquaflow]

So recently (within the past 2 weeks) I have been noticing some severe performance issues with my system. To give an example, I used to be able to run EFT at probably about 150fps+ on smaller maps perfectly fine, however recently it's as if I'm capped at 30 FPS, I almost never break it and if I do, it never gets above 40-50 FPS and it isn't stable. As far as I know I haven't changed anything really since then, I've added some peripherals and probably downloaded some things, but I am near certain I haven't downloaded anything bad. The awful performance is not consistent either, on some occasions the game will boot up and run very nicely, only to go back to the 30FPS max just an hour or two later. I have made sure there are no programs in the background sucking up resources. Task manager also shows that my GPU utilization is relatively low, but occasionally spikes to very high percentages and I don't know why. However, neither my GPU or my CPU run at consistently high utilization so I don't think it's a case of bottlenecking with either of those two parts. Online the only result I'm getting is to make sure my power settings are all good, and they are, I've set them to Ultra and have experienced no change in FPS. I honestly am clueless... any help is greatly appreciated!

SPECS:

https://imgur.com/a/Yrnzbsn