What does this crazy scary Dream mean??? plz help?

well the part about the screaming and no sound coming out happens to me allot too. it wasent holding you down in the dream it was like if your brain thinks your awake but your body thinks your asleep. the command to scream or move is too weak since your sleeping and if your brain thinks your awake the command wont work in your dream either. white is a really calm color sometimes thought to represent purity or a saint. and you described the thing as a demon so it could be telling you someone you know is a selfish person or has a mixed personality if its wearing a devine color on the outside but its demonic on the inside. i wouldnt think of it on a large scale like maybe someone you trust being your friend for personal gain