She is overtaken by a sensation of unbeing. There is no other word for it.

her eyes closed against some
unimagined darkness, where she is buried in an ache
in which nothing makes
sense.

The awful shadow of some unseen Power Floats though unseen among us; visiting This various world with as inconstant wing As summer winds that creep from flower to flower; Like moonbeams that behind some piny mountain shower, It visits with inconstant glance Each human heart and countenance; Like hues and harmonies of evening, Like clouds in starlight widely spread, Like memory of music fled, Like aught that for its grace may be Dear, and yet dearer for its mystery.

I was oppressed with the sensations I then felt; I sunk under the weight of them.

...and see ominous clouds of inferiority beginning to form in her little mental sky...

She felt the abyss of disenchantment.

A shadow leaned over me, whispering, in the darkness,
Thoughts without sound; Sorrowful thoughts that filled me with helpless wonder And held me bound.

Those who had before known her, and had expected to behold her dimmed and obscured by a disastrous cloud, were astonished, and even startled, to perceive how her beauty shone out, and made a halo of the misfortune and ignominy in which she was enveloped. It may be true that, to a sensitive observer, there was some thing exquisitely painful in it.

She was a foreigner and, like all foreigners, she carried with her the shadow of an elsewhere.

But her's was the misery of innocence, which, like a cloud that passes over the fair moon, for a while hides, but cannot tarnish its brightness.

It was something quite special, that feeling: an oppressive, hideous constraint as if I were sitting with the small ghost of somebody I had just killed.

With the ebb of lust, an ashen sense of awfulness, abetted by the realistic drabness of a grey neuralgic day, crept over me and hummed within my temples.

Being oppressed means the absence of choices

The thought of him was a smoky cloud from hell that moved and crept in her head.