Low fps

Try reinstall the game, remove your current config autoexec ... and enable Multicore process

Maybe try to fix Settings... clean up old files for sure !

Try using CC Cleaner to clean the cache in your computer. It might help.

Try this in console
fps_max 0

and update your GPU driver

If you have all graphics set to low you can play with the launch options, but at the end of the day the best answer is to upgrade your PC (CPU) for a solid FPS boost.