All this time, you were becoming your dream goth girl, while also somehow developing feelings for Mark, as if your mind is telling you that he is your dream love interest. You decided to take the ring off, before Mark did something, but noticed that it wasn't on your finger in your dream, and just then it was too late for you.
Mark bit your neck with his sharp vampire teeth, as blood oozed from your neck, causing your ring to glow one last time, and you feel your genitals shrinking. Your penis gets fully erect, and then shrank all the way, with every drop of cum spilling out, until a womb forms in your body, and the shrinking rod gets replaced with a big pussy. Finally you woke up, and find that you were no longer in the library, but instead the bedroom in your own apartment, as you stretch after waking up.