Turn the texture quality to manual and leave at normal settings....otherwise memory leak occurs and game/pc end up using 7gb+ out of the 8..
If you are meaning you cant start up at all try in safe mode (game not pc...if it offers that option) after exiting via task manger

If you are meaning you cant start up at all try in safe mode (game not pc...if it offers that option) after exiting via task manger