Re: Computer Problem
You can run a virus scan if you want... I would suggest Malwarebytes.
It's a laptop, at the beggining of your post I would have suggested it was overheating. I see that it ran at 60 FPS later. That would suggest you play your laptop all day every day... then suddenly you left it off for two days, picked it back up and played all day every day again. Download HW Monitor. Look at the temperatures of everything before you start the game. After it goes from 30fps to 20fps look at it again. See if the temperatures are lower.
If you have a green light, but you see a car out of the corner of your eye run the red, you're going to stop.
You don't want to crash into the other car. The pieces of hardware don't want to overheat. Best I can tell you is the performance of the card decreases while heat increases.