I Am Possessed By A Demon, Spirit Or Soul

I am possessed by a very disgusting devil that attacks innocent people for no reason and actually enjoys it. He controls me in very abusive ways, and tries to hide the fact that he is possessing from my family. He sends severe stabbing pains in my body and it even takes me on by surprise. He mocks me severely. He does very horrile things to me. And I hate him. How do I get rid of him and all demons in my body and strip them them of their powers for free? Does anyone know people that exorcise for free?