Eve's Return - an Urban Fantasy novel, by Crystal A Bourque

http://www.amazon.com/Eves-Return-Book-Crystal-Bourque-ebook/dp/B00GVL6T4I
After having her heart broken, Jordan Andrews drops out of university to travel the world and ‘find herself’. Without a penny to her name, she returns home, only to discover a terrible tragedy has occurred in her absence. 
Determined to find her elusive twin brother, she does her best to ignore the terrifying hallucinations that begin to plague her. 
It quickly becomes clear that Jordan’s hallucinations are very real. She is attacked by a hoard of demonic creatures, but is rescued by a woman who claims to be a warrior angel. Through her, Jordan discovers that she has a power that is too strange to believe, and a seductive past that proves to be too irresistible to ignore. 
Now, Jordan must not only find her brother, but also obtain an ancient artifact. It is her only clue in discovering more about who she is, and the role she is destined to play.