Computer starts stuttering/dropping frames

[Swhitlock]

FIrstly, my set up:
CPU: i5 8600k
GPU: GTX 1070 ti, 8gig
RAM: 2, 8 gig ddr4 3k mhz
Storage: 512 gig m2 SSD
Motherboard: ASRock z370 Killer SLI/ac
Powersupply: evga 850 supernova
Monitors: Main, Benq 144, Secondary Benq 99, and a 55 inch samsung 4k

Okay so about a month ago I noticed my computer had started to really lag, sometimes acting like it wants to out right freeze on every game I play. Like I'll be playing CSGO and my fps is 200+ and about every 45secs-1 1/2 mins my game will seem like its running at 5-10 fps for 2-3 seconds.I noticed that if I restart my computer the lag/fps drop will go away for about 30mins to an hour then slowly start getting worse.

I had thought my GPU or CPU was overheating but my cpu and gpu never gets over 55c and thats after hours of gaming on even demanding games. I had also thought maybe I had a memory leak so I left resmon open on another monitor and it never stays at a high percent.

Is there any suggestions on what to do, what to test for, anything I could do to try to fix this because its really a bummer after spending so much building this computer.

 

[tennis2]

Was working fine, now not. Sounds like a software problem. Have you run any thorough virus scans or checked background processes?

 

[Swhitlock]

Was working fine, now not. Sounds like a software problem. Have you run any thorough virus scans or checked background processes?

I bought and installed bitdefender yesterday and did a full system scan and it didn't find anything. I have checked my processes. I havent seen anything eating at my usage but I'm not 100% on some of the small things that are running.