I see ghosts all over my housee?

me and my friends played with the Ouija board like 5 times I think... but now i have nightmares about ghosts... not only do ii have nightmares, but i wake up and BAM there they are. I've never believed in these kinds of things before, but now they're really creeping me out. Sometimes I see a green grim reaper face thing spinning over my fireplace, and other times I see a ghost that looks like a person with a sheet over them with red triangle eyes.. I'm trying to convice myself it's not real, but I don't know..., it seems really real. Help?