PC staretd lagging out of nowhere! Please help

Hello guys! I'm struggling with a problem that i can't solve for like half a year. So, I have a GTX 1060 6GB TURBO, 16GB DDR4 Samsung RAM and and Intel i5-7600. I got it in July 2017 and everything was fine. For e.g. GTA V was running 60FPS stable with VSync on and some of the advanced graphics on. After some time, January-February this year, to be exactly, my PC started lagging in games. Now I have a lot of FPS drops in GTA (from 60 i get sometimes to 58-45) wich I never got before. NFS Payback has fps drops as well as CS:GO, PUBG, Forza and other games I play.
I've went to a lot of forums and FB groups asking for help.. and I did everything what people told me. I even tried to disable that Meltdown or idk how it was called protection with InSpectre. I checked my PC with different antiviruses (Kaspersky - wich is my main one, and Malwarebytes. With the second one I tried also to check for viruses in safe mode.) and none of them found anything.
My temps are normal (like 70-80 wich I had everytime)
Also, three weeks ago, my PC got cleaned (i mean the interior of it) but still, the problem is persisting.
I update all of my drivers etc regularly.


Also, I didn't play anything for like 1 week or so and GTA seems to lag even more...

NOTE: I updated my GPU driver yesterday but everything still lags.

Can you help me please? I'm trying to find a way to get my pc back to normal. As I said, I'm struggling like almost halp a year. PLS HELP

NOTE: I posted this in the PC GAMING forum too, so pls don't mind. I didn't know what's more suitable so i chose both of them. Hello guys! I'm struggling with a problem that i can't solve for like half a year. So, I have a GTX 1060 6GB TURBO, 16GB DDR4 Samsung RAM and and Intel i5-7600. I got it in July 2017 and everything was fine. For e.g. GTA V was running 60FPS stable with VSync on and some of the advanced graphics on. After some time, January-February this year, to be exactly, my PC started lagging in games. Now I have a lot of FPS drops in GTA (from 60 i get sometimes to 58-45) wich I never got before. NFS Payback has fps drops as well as CS:GO, PUBG, Forza and other games I play.
I've went to a lot of forums and FB groups asking for help.. and I did everything what people told me. I even tried to disable that Meltdown or idk how it was called protection with InSpectre. I checked my PC with different antiviruses (Kaspersky - wich is my main one, and Malwarebytes. With the second one I tried also to check for viruses in safe mode.) and none of them found anything.
My temps are normal (like 70-80 wich I had everytime)
Also, three weeks ago, my PC got cleaned (i mean the interior of it) but still, the problem is persisting.
I update all of my drivers etc regularly.


Also, I didn't play anything for like 1 week or so and GTA seems to lag even more...

NOTE: I updated my GPU driver yesterday but everything still lags.

Can you help me please? I'm trying to find a way to get my pc back to normal. As I said, I'm struggling like almost halp a year. PLS HELP