Visual field test normal w/minimal peripheral vision loss. After diagnosed w/glaucoma feel more nervous driving such as changing lanes. Psychological?

MAYBE. Ask ophthalmologist to check visual accuity. If there has been no change, youre getting unnecessarily anxious. Remember the possibility of trouble doesn't mean it's there now.
Not neccesarily . You may feel more nervous for other reasons. Decrease is visual acuity, diminished night vision, slower reflexes, better knowledge of the potential risks of driving. Assuming your vision is normal, just relax and slow down a bit.
Probably. . Early glaucoma field loss does not cause widespread peripheral vision loss. It usually is subtle, sectoral- not total. Follow your doctors treatment regimen to prevent porgression.