Scripture tells us
“When an unclean spirit goes out of a man, he goes through dry places, seeking rest, and finds none. Then he says, ‘I will return to my house from which I came.’ And when he comes, he finds it empty, swept, and put in order.
Then he goes and takes with him seven other spirits more wicked than himself, and they enter and dwell there; and the last state of that man is worse than the first. So shall it also be with this wicked generation.†(Matthew 12: 43-45)
In short, when we are redeamed and the demons flee, we MUST not leave them a vacancy to return. If this is a fight you have fought this long, then the desire for deliverance must be strong. You must CONTINUE to pray and thank God for you deliverance DAILY. Be in God's word DAILY. Pray/worship him DAILY. If the doctor prescribed a medication that got rid of the presence then you would take it DAILY. You know this battle is set before you, continue to fight DAILY. And be SO FILLED WITH THE HOLY SPIRIT that the demons have no place to come home to. God wants that empty space to be filled up with His knowledge, presence, and grace – and the only way that can happen is if you start growing and maturing in the Lord.
As for churches....yes the holy spirit bestoys different gifts on different people, and some are given the gift of healing. BUT you have to remember, it's the SOURCE you seek, not the person. I'm not saying that your "doctor shopping" amongst chuches...but it sounds like you may. Find a church where you can WORSHIP GOD. Remember we are here to serve HIM. And only when we put him FIRST (getting rid of our vicses, striving to live FOR HIM), can he do the work in us he desires. HE gave us free will...so WE open/close the door to miracles in our lives.
THe other scripture that come to mind is the father whose son has not yet been healed of demons. He has taken the boy to doctors, healers, to Christ own deciples who have cast out other demons. WHy haven't they been successful. Christ tells them that some demons can only be cast out thru pray and fasting (which requires time spent with god, giving up anything that seperates us from him). And the father has lost faith in his son healing, but he has been trying to get him well for so long. Christ tells us that our FAITH, true faith without doubt, answers our prayers. THe father ask God to give him more faith, faith anywhere doubt is lurking and he is healed. Christ miracles are discussed after his time in prayer and fasting. He reminds us that our healing comes thru our faith. Ask God to lead you to scriptures that you can cling to. He loves you. He wants your deliverance!!!