J.L.
My daughters were freaked out by the "automatic" toilets. We used to cover the sensor with a piece of toilet paper (others told us to carry post-it notes to use to cover the sensors that are on the wall). It really helped, but they were still very anxious. Hang in there! I wouldn't make her go back to diapers, just try to get her to relax. Have her sit on a "potty" and watch a movie or something until she feels more comfortable. Good luck.