The 7,000 Souls of Alma Drake

Alma Drake was a typical suburban college student before she was turned into a Succubus by her less-than-perfect boyfriend. Ian turned out to be a powerful soul-sucking Incubus with a harem of other Succubi feeding him souls. Now Alma's up to her eyeballs in soul debt and flat broke in terms of real-world cash.
She can't turn to her friends because she had to drop out of college to keep from accidentally killing her classmates. Her mom, who thinks Alma's a junkie, sleeps all day and stays out all night. And Alma can't run away, because Ian... well, Ian always finds her.
Shadowy figures have begun stalking Alma's hunts and chasing her through the night. If she could, she'd just hole up and hide, but she's driven out by her insatiable thirst for the souls of men. After all, a girl's gotta eat.