Carmilla by Kim Turrisi

Newly escaped from the stifling boredom of a small town, college freshman Laura is ready to make the most of her first year at Silas University. But when her roommate, Betty, vanishes and a sarcastic, nocturnal philosophy student named Carmilla moves into Betty’s side of the room, Laura decides to play detective.

Turns out Betty isn’t the first girl to go missing, she’s just the first girl not to come back. All over campus, girls have been vanishing, and they are completely changed when (or if) they return. Even more disturbing are the strange dreams they recount: smothering darkness, and a strange pale figure haunting their rooms. Dreams that Laura is starting to have herself.