Am I being haunted? If so, is it a ghost or a demon

Ok, so recently strange things have been happening to me and my close friends. It started happening about a month ago, we were having a sleepover and watching paranormal activity one at three o'clock am, and suddenly we hear slow, heavy footsteps on the floor above, then quick running, then the light flicked on and stayed on for about five seconds, then it flicked off. There was more running then heavy footsteps, then it stopped. We were so scared one of my friends was huddled under the covers and practically crying. Granted, my friend has little sisters, who are about the age of eight and nine, but this was at three o'clock am. We still haven't figured out what happened. The next week was fine, nothing abnormal, but the following week it got more aggravated. My room door slams shut, we see shadows and things that don't look human lurking in dark alleys or in a meadow behind my house, the smell of blood, I wake up with scratches on my hands, legs, and sometimes face. The scratches are small, but deep, sometimes they appear to be bite marks. My friends get mysterious phone calls, and inanimate objects move on their own. Sometimes my hair even gets pulled when I'm in my room, and whispers, the whispers are unintelligible, they are not in a certain language any of my friends or I can understand or recognize. My friend seems to have it the worst of all though. Her sound system turns on and off, sometimes even playing two songs at once. Her little sister shares a room with her, and the toys she left on her shelf were scattered around the room. Her personal possessions become broken and mutilated she even gets death threats scrawled on the side of her locker. I am still the only one in my group of friends to have physical contact happen.

At first, I thought this was a troll thing: Paranormal Activity and once I saw this movie about how 3:00 AM was the portal for demons or something like that. Have you been blacking out? Scratches and bitemarks might be from a cat. Phone calls and locker threats should be dismissed as pranks- Anyone otuside these girls know about this? Demons have been known to speak foreign languages. I would pay no heed to the cat, because cats are like partners of evil. And I'm not saying that just because I dislike cats. The physical violence, moving objects are most likely demons. Electronic malfunctions are probably caused by the electric energy radiating from demons. As for the crucifix..