Your presence (is haunting me) (слэш)

SPNReverseBigBang Prompt
Sam always thought that no one would ever understand how it felt to be possessed by Gadreel. How he had felt to be precise. Because it wasn’t bad, far from it, he couldn’t remember a time in his life when he had ever felt so safe and happy as when Gadreel was there with him without even knowing it. He wanted that back. Not being possessed by Gadreel again, no, he figured that Gadreel's presence himself gave him these feelings. So he wanted him, Gadreel, back. Wanted him close. He dreamed of it. Sometimes he could even pretend to still feel him like a ghostly presence around him and that made him feel better. Often Sam questioned just how stupid he was to be in love with an angel long gone… or was he?