Is the game unplayable as in it doesn't work at all, or simply has too low framerates?
At what resolution are you playing the game? Fallout 4 needs a better card than the GTX 1060 for anything at 1440p and above on Ultra. The GTX 1060 is most probably the reason if your framerates are too low.
But try updating all your drivers to the most recent first before anything else.