I need help with a demonic problem?

For my entire life I have been followed by what I have now come to realize is some sort of demonic creature. I have seen things, heard things and felt things and I know I am not crazy. This is something that has followed my family for generations and I am the one it chose to focus on for this generation. I'm concerned for myself, but not especially because, as I said, this is something my family has been dealing with for quite some time. I'm concerned for my best friend. Last year I opened up to her about it and now she is suffering as a result. She's heard crying when nobody was, voices whispering, and once a young girl beside her bed in an old fashioned night gown that had black eyes. But most recently, she saw a cloaked black figure that was around 7 feet tall that lacked a face. She said he had some sort of hat on...she describes it as a fedora looking hat with a longer brim. And when she talks about these things she cries and shivers and the room feels as if all the warm air has been sucked from it. This is a symptom I share. I too have seen and heard things and as long as I can remember, knew something was always there with me. I know it is something that is not human and never was. I know my friend is telling the truth and I will ask you not to doubt her as well. I want only believers to leave answers. Thank you for your help.