Alpha R2, performance problems, solved on Steam

so I was playing far cry 5 and having fun on my alien alpha r2 when all of a sudden the fps went from 30-40 fps  to 10-5 and it wouldn't go back up, when  I felt my computer i noticed it felt extremely hot. so I exited the game. processor is intel(R) Core(TM) i7-6700T, graphics card is GeForce gtx 960, and my pc has 8GB ram. I noticed that when I start a game it slowly uses more and more of my cpu until its being 100% used up and that's when my games start running terribly