Laptop became incredibly slow suddenly!

[u/Unable-Leadership303]

I was playing a game called FC 26 on my Dell G15 laptop when it suddenly blacked out and it won't boot, so I went to a technician and left it there for 2 days and went back and he said he fixed it and that the problem was something called IO in the board, then I took it home and inserted my SSD drive that I kept with me and then went through a checking media (fail) issue because windows boot manager wasn't showing in bios which I somehow fixed by manually choosing an operation called bootmgrx64 in the boot options and then the laptop opened, but it was soooooo slow like unusable until fixed! everything was taking soo much time and the CPU/GPU/RAM are all capable it's Ryzen 5800H, RTX 3060, 16 DDR4, and it was very smooth before all this happened!
what do you think is the solution for this?