Having an issue with fps

Not so much of a bug but still needs to be fixed. I have been having an issue with fps with the new version that just came out, this has never happened to me before and I always got a constant 300 fps before the update. But ever since then, im only getting around 20 - 40 fps even on the lowest video settings possible. Please fix try to fix this, maybe by adding a low detail mode or low-end pc mode that makes the graphics look less clean? I don't know why this is happening and if you can solve this or tell me a way to solve this that would be greatly appreciated. - Yours In Regards, Ian