The Wave by Algernon Blackwood

The conflict in Tom's puzzled heart sharpened that evening into dreadful edges that cut him mercilessly whichever way he turned. One minute he felt sure of Lettice, the next the opposite was clear. Between these two certainties he balanced in secret torture, one factor alone constant -- that his sense of security was shaken to the foundations.

Belief in his own value had never been thus assailed before; that he was indispensable had been an ultimate assurance. His vanity and self-esteem now toppled ominously. A sense of inferiority crept over him, as on the first day of his arrival at Alexandria. There seemed the flavour of some strange authority in her that baffled all approach to the former intimacy. He hardly recognised himself, for, the foundations being shaken, all that was built upon them trembled too.