In the eyes of God the possession doesn’t exist. All people touched by spiritual problems, even very seriously, are still the children of God. They are loving by Him so deep in that time, getting the special protection from God’s angels.
This is a lack of balance. God knows about, letting for this process and controlling it. Never you are in the ‘hands’ of beings called demons.
You can ask for help the Prayers, it’s perfect but always remember – you are the only one person able to stay in touch with God and finish the ‘possession’.
They will tell you /preachers/ that you probably broke some rules. NO. Many people, families is just attacking. The reason is not in 10 Commandments, . the reason is in the rule how our physical and spiritual worlds have been created.