Reinstall the driver with a factory reset, and delete everything that might be saved, and this should solve the issue.
I too have had my graphics card gone crazy after a driver update with me loosing like 100 fps and Fortnite being a stuttering mess, but this seems to have been some driver conflict or update error, and was fixed with uninstalling the current version with a factory reset, which is found directly at the beginning of the driver installation. After this, the program will ask to reboot the computer, and then the installation continues when entering Windows.
I hope this helps, and good luck!
