Lagging, Overheating MacBook Pro 2014 after Big Sur update

Hi, so i have a MacBook Pro Retina 2014 13" , and a few weeks ago i updated it to macOS Big Sur from catalina and after it was done updating i noticed that all the animations were very very choppy, and scrolling in safari was just bizarre. at first i thought "well, maybe it was just doing some icloud backup thing or whatever" , but then it persists to lag and almost felt unusable as it occasionally freezes, especially when i tried to use Photoshop and final cut pro. it also overheats on the top right part of the keyboard where the cpu is. even messages app seemed to lag very badly when scrolling. so then i decided to downgrade the os back to Catalina all together because it got very annoying to

work on. after i downgraded it to catalina, the same problem that wasn't there before i updated to big sur continues to occour.. so i thought, maybe the thermal paste was just dry and i needed to replace it, so i replaced the thermal paste and yet the same problem continues. i also checked the performance benchmark on geekbench and noticed that the metal performance is 0..

i am so confused about what seem to be causing the problem.. and i kinda need it fixed asap.. Any ideas what might be causing the problem? is it a hardware problem? or did macOS Big Sur just destroyed my Mac? :\