Everyone In This Room Will Someday Be Dead by Emily Austin

Meet Gilda. She cannot stop thinking about death. Desperate for relief from her anxious mind and alienated from her repressive family, she responds to a flyer for free therapy at a local church and finds herself abruptly hired to replace the deceased receptionist, Grace. It's not the most obvious job - she's queer and an atheist for starters - and so in between trying to learn mass, hiding her new maybe-girlfriend and conducting an amateur investigation into Grace's death, Gilda must avoid revealing the truth of her mortifying existence.