It is good to acknowledge the reality you're in. Demons are very real and can quite easily get inside our lives to mess up things. Don't you believe the fairytale that demons are unable to mess you up, cause you profess that you are a christian. Jesus said, that he who does what I command, he is my disciple. So, you see - not everyone is a believer, even thou they claim to be. It's true. So.. first things first; you should ask and seek out a real pastor (in your local church, preferably) and tell everything - starting with the story of how you became to be a follower of Christ Jesus. Once this is done, it is easier to evaluate how to proceed. Demons are having a field-day with self-claimed christians all over the world, cause they serve their own flesh, not being obedient to the commandments of God, given through Christ Jesus. In every good thing, patience, love and obedience are key factors. May our heavenly Father guide you, in your search of a good local pastor. Amen.