I'm trying to find a short story that I've read years ago.
It's told from the perspective of a vampire-like person who awakens in a forest at night, and everything around them glows faintly with life. They are horribly cold and hungry, and find that eating something nourishes them a little, so they eat some mushrooms and grass.
Eventually they stumble into the river, and it drains all of their life away and nearly kills them, but when they emerge again they come across a cabin with a man in it. If I remember correctly, the man shines as bright as the sun with life, and they end up ferociously ripping their neck open to drink as much as they can of his blood, which to him is glowing with life and warmth.
Then I think another guy shows up and kills the main character, who was a vampire? Can't remember..
Anyway, that's as much of the plot as I could remember. Which story was this? I think it was in some anthology or other.