I am sorry to hear that your preceptor is being rough on you. I am also a new grad, and I did my practicum in the ED, and have now joined the team. My preceptors was great during te practicum, and will be starting my new employee orientation. The charge nurse that interviewed me told me that some nurses will "eat their young". She told me that if it felt like the preceptor, or any other nurse, gave me that feeling to go talk to her immediately. If I were you, I would speak to your nurse manager, charge nurse, or the dept educator. Good luck!