I need help, please help me!?

I recently saw the movie paranormal activity with my mum and halfway through she stared talking to me about how, when she was in Uni, she did a ouija board with a bunch of her friends. In short, it worked and affected all of them VERY badly. 2 ended up leaving the school. I asked to do it with her but she refused as she had promised herself never to do it again. I got quite freaked out. And then that night i had some of the worst nightmares of my life, about the devil and such. At one point i remember sitting up in my bed ( i dont know if this was in my dream or i was awake) and looking at the mirror ( which is right in front of my bed) and looking myself. but it wasnt me, it was this pale person with no face and it started moving towards me and i screamed and my mum walked in and she had had the EXACT same dream. I never believed in any of this before, i was ver cynical, but i need this explained, i am so scared