Similar kinds of 'irrational' fears are well-documented among some of the best and brightest out there. RAF medical literature, from memory, identifies phenomena such as a feeling of fearful loneliness flying between 8/8 layers (often cured just by making a radio call), and the alarming sensation of being balanced on the point of a needle at altitude.
One up to Pprune that people feel they can talk about it here. Probably no better solution than sharing it.