I had a gray out. Lost all vision in one eye temporarily while working online and getting stressful email. What was that?

Get checked. May have been an ocular migraine, but another possibility is amaurosis fugax, related to impairment of blood supply and possibly associated with increased risk of stroke. You should have a dilated eye exam, screening for blood pressure/cholesterol and possibly additional testing such as an ultrasound of your carotid arteries.