Games start lagging/stuttering out all of a sudden on my razer blade 15

Hey everyone, ever since april, i’ve noticed that when i’m playing a game, after about 10-20 minutes the graphic quality goes down significantly and the FPS drops to about 5-10. The game’s barely playable and my laptop slows down too. I’m using a razer blade 15 base model from late 2020. When the issue first started, it was due to razer cortex. I got rid of it and then everything was fine for a while. Then i noticed that it also happened whenever i had my controller plugged in for too long so i upgraded to windows 11 and for a while everything seemed to be fine. But as of recent, it started happening again where my games just start lagging like crazy all of a sudden and i can’t figure out how to get rid of this. I play AAA games like rdr2, fallout 4 etc and it’s impossible to run the game for even half an hour before they start stuttering. I’ve read other user’s posting about the same issue and even re-applying thermal paste doesn’t work. Is there something in my PC that causes the games to stutter? i got rid of razer cortex which is known to make games stutter. I don’t really have the money to upgrade my laptop and this is all i have for playing games. I’d really appreciate if someone tells me what’s wrong and what kind of issue this is. Thank you so much in advance