Heights terrify me, and too much time was spent overplanning for a nightmare that never happened. In retrospect, the AT has a lot of "you gotta be kidding me moments" as opposed to scary views. Lehigh Gap and to a much lesser extent Baldpate East were scary to me, while Katahdin and Wildcat Mountain (full disclosure: it was VERY cloudy) didn't come off as places you could fall from.
Focusing on your hand placement and footing means there is no time to dwell on the fear of heights. Years ago another WB member said something to the effect "don't let your fear of heights limit your experience on the trail". I think she nailed it.