Hi there
This is Tamal trying to help you with the issue.
Sorry to hear about your misery. Please provide your PC specification or model details to help me understand the issue better.
General slowness can be attributable to presence of HDD instead of SSD as system disk and low amount of RAM (less than 8GB is considered low for a windows 11 PC). Other reasons can be PC is thermally throttling due to loose contact between Processor and GPU with the thermal solution. Power supply inadequate or loose contact in power connectors can also cause intermittent lag. As fans spin furiously two factors are possible in your PC, throttling and the first two reasons I mentioned.