Question R9 290x suddenly drops frames..

[poustis]

Hello, I recently got a 144hz screen and tried it on my system (i5 4460, r9 290 trix sapphire). I installed all the drivers and had no issues playing csgo (200 +fps). Suddenly after my first competitive game, my frames dropped to 120-90. I re installed the drivers, both new and old, but no changes. Msi afterburner doesnt show any high temps...Any clues??
And here's my pc specs:
Desktop
OS:win 10
CPU:i5 4460 stock
Motherboard: asrock
RAM:16 gigs ddr3
GPU: r9 290 trix sapphire
HDD: 1tb
PSU ; corsair 750 wat, since 2014

 

[RARRAF]

And here's my pc specs:
Tablet/Laptop/Desktop/
OS:
CPU:
Motherboard:
RAM:
GPU:
HDD:
PSU make and model and age are helpfull
HWINFO from here https://www.hwinfo.com/download.php