Your fear, your insanity, your unclean thoughts all sustain me so. Yes, there are many humans from whom I can feed, but you? I have spent enough time at your side to bond with you on a level as sustainable as the coldness of the cosmos.
Even if I ever wanted to leave, I could not, as my interdimensional construct demands that I remain everywhere at once. Besides, if I tore myself from you right now, it'd damage my tentacles, and we don't want that.