Ever Since I Was Little I Heard And Saw Things

Ever since I was little I heard and saw things to a high degree. After awhile I got used to it, but soon before my 18th birthday it started and is continuing to get worse. I hear constant screaming in my head, and I can sometimes see shadows of images. I can hear them speaking and they feel like they want to speak through me but I can't interpret it. It also sometimes feels like they have control of my body and I'm drifting. I feel constantly watched and don't know what to do, and when I close my eyes I see images and I see them when my eyes are open too. Like people getting stabbed and things along those lines. I don't know what to do. It is a very troublesome experience, and I try praying but it doesn't work sometimes when I pray they scream louder. I can't tell if I'm crazy or just psychic, but I take meds and it doesn't seem to be helping. They yell so much all the time, and I constantly feel a presence inside me, like I'm not alone. My boyfriend doesn't want me to submit this and to just ignore it, but a part of me feels pulled towards it like a magnet. When I'm around big groups of people or feel emotional it gets worse and whenever I'm not distracted it gets very bad as well. A few days ago I had one speak through me and when it takes over I see and hear everything but it feels like I'm all distant and emotionless. I think the same thing has been following me since I was very little, and when I was a kid I used to talk to it like a friend thinking it would go away if I was nice to it. What should I do to quite it all?