Unexplainable Encounters

It all starts back about 2 years ago now, my grandparents passed away and left their house to my family and I. The first few months living in the house was normal, nothing out of the ordinary. Until one night I was upstairs laying in bed. I had closed my eyes to go to sleep and I heard walking up the stairs an scratches on the walls I thought nothing of it do I closed my eye, only to wake to a slap across the face. I immediately ran down stairs to my parents. Months had gone past and nothing had happened so I forgot about it. Until one night I had friends over and decided to make a ouija board we sat in my attic that attaches to my room and tried. A spirit spoke to us, a few words then a couple of numbers and letters we closed it an sat there for a bit all of a sudden my friends started crying for no reason we didn't no what to so we tried to talk to her she didn't reply all of a sudden she stopped sat up and just stared at nothing, she didn't blink for atleast 20 minutes an did not move. When she snapped out of it she couldn't remember a thing, later that night she was leaving and when into an altered state an grabbed my face and said it's still there don't go in the attic I asked her what she was talking about and she said she didn't know something made her say it. I did not sleep in my room for weeks but since I have been sleeping in there things happen. I have seen shadow, my door unlocks and open, I hear voices and snoring from in the attic, I have dreams and wake up with a lady yelling in my face, I see spiders for atleast 10 seconds then they dissapear, I dream of finding devil books in the attic with symbols and the most recent thing to happen is my alarm going off at 3an and my dog barking at the attic. I know it may sound strange but if someone could please help me I would really appreciate it, I am scared and have no idea what is going on!