Having nothing is even worse, your mind conjures up the horror of nothingness.
You think of nothing, therefore you don't think, therefore you are not. In short, Universal Truth will never let you escape the scariness, it is infinitely mutable and panontovoric.

Keep in mind that the whole mission is just a visual metaphor for things happening inside your brain, sleep tight!

The best way to escape the flashes would be to A) face them during day light with a friend or something or b) disabling the SEXPs, which would bork the mission.
I tried looking at the images outside of context, sadly UT finds a way to make them scary again. It's the bloody context that gives them that property.
Edit:
"Seeing flashes of the apocalypse and acataleptic entities isn't normal, but on Nagari it is. Nagari, not even once."