Hi! Call me Life ! I come here because i need help!

Hi! Call me Leaf. I want to be an Onmyoji because when i was a kid a demon kiddnaped me and take one of his servants inside me. I was possessed by a demon but i tricked him in battle. I close him and me in the room closed by a key inside my soul. This looks like a demon boar and looked angry when I walked inside my soul in a dream. I protect myself from it but at great cost. I does not remember anything from happening was when I closed myself and the demon behind the door. I fogot who i am. I remembered only brief moments before this event. I want to learn how to exorcise this demon out of me and wants to learn how to fight this demon who kidnapped me I remember how he say "I'll let you live now but when I get a all i need I will come after you and I'll kill you" Sorry for bad english ; )