My program takes a lot of cpu usage for no reason

I play csgo competitively and we play on a client named esea. The client itself isnt really important, doesnt take much physical memory but sometimes its cpu usage goes up to 13-15% and it can stay up there for like 20 mins, then go back down to 0-1.
here are some screenshots : https://i.imgur.com/wgix05b.jpg https://imgur.com/wgix05b,PXUC0P1#1
It brings my fps down a lot and makes my game really choppy.
Hardware : fx-8350 @ 4.2 ghz
gtx 660
12 gb ram @ 1600 mhz
cpu cooler : evo 212

They have a support system as well but everything they told me to do didnt work. What I've done so far :
-uninstalling AV and reinstalling the client
-disabling AV when opening the client
-running the client in administrator mode
-Use only one cpu for the client and 7 cpus for csgo
-Formated my SSD

Thanks