Loss of Love
with almost a shock. You could end the story on this moment of negative ‘epiphany’, or you could develop it further towards the person’s adjusting to this - to a sense of failure, or sudden loneliness, discontent, or however they/you see it.
It suddenly occurs to me that you might think how it came about that Judas suddenly lost his love of Jesus, or was it sudden? Or was there, as there is in some people, some sort of ‘inability to love’.
What you write needn’t focus on the lost person, or object, or place. That is it needn’t be a lament. It could simply deal with the life of an unhappy person, revealing the reason only at the end by his or her looking at a photo or breaking into tears at the sight of a picture. Then, again, it so often happens, that someone who has been without love for a long time may not longer realise that they want or need it. Or they may have been trained never to ‘give’ themselves or make themselves vulnerable, to have that ‘stiff upper lip’.