Knee jerk idea.
Take the card out and replace the old setup.
Agree you must be able to see to deal!
Honestly I have no idea why you are so aflicted because if the card was loose you wouldn't have been able to load the drivers.
It may have slipped out of the slot a little but if it happened while rebooting that is stretching coincidence.
Another possibility is the wrong drivers or too much asked of your monitor.
Others will add better ideas