Where the Light No Longer Follows by Wendy Heiss

Time no longer exists. At least not to Silene.

Serving under the God of Death as a Reaper, she finds herself stepping between life and death every day, collecting souls and guiding them towards the afterlife. When the brother of Death begins interfering in her duties, she begins to question her existence and purpose.
And the closer she comes to finding her answers, the further her current reality sinks deeper.