Mouse movement= Fps drop

So I just got into league like a month ago and everything was going fine until about a week ago when during the game i would lose fps when ever i moved my mouse. Normally i would get upwards of 200 fps but whenever i rapidly moved my mouse i would go down to 6 fps. This has made me stop playing the game entirely and searching through forums on how to get it fixed. Most of the forums said it was a process called stij.exe but that doesn't show up in my task manager and i recently found that someone said that it maybe overwolf so i uninstalled it but it didn't fix anything. Specs AMD Radeon RX-480 AMD FX-8350 Don't know much else D: