Dreams can be very vivid. I one time had a dream where my hair was stuck in a chain like fence. Then I woke up to find that a piece of paper with gum on it was stuck to my hair. "Stupid girlfriend and her habits of saving gum for the next day!"
I would look for signs of bruises first. If there are none, and this seems to be a reoccurring thing, you should try getting a dog and monitoring it's behavior.
I don't believe in things I have never seen. But I have heard of these things being real. The few friends I have that claim to have bared witness to demonic activity all share the same things in common... they believe! I have heard that you are more vulnerable to attacks if you believe, because believing is a way of opening a doorway for them to get into your life and mind. I mention the dog because dog's seem to have a sense that makes them able to see or feel the presence of these dangers. In one instance, I had a friend who went through demonic attacks and woke up everyday to find his dog locked in the shed. Creepy was that there was no way for the dog to get in there and push the cinder block against the door from the outside!
Good luck! Wear a cross!