Awww Jane,
Poor you, I'm praying for you that our almighty, wonderful, loving and caring God will sort out whatever's going wrong in you. So how and when do you think you became demon possessed? I Firmly believe that demons / Satan are impotent against the Holy Spirit and that they cannot enter and control a believing disciple of Jesus. There are just two accounts of believers who had bad spirits take over them in the Bible and both were 'ex-believers' who'd turned their back on and rejected God's way, namely King Saul and Judas. That you are on here seeking relief from your problem and asking for God's solution to it tells me loud and clear, that you're not of their camp - at all!
IMO Satan has an inflated opinion of himself and tries to claim credit for everything that goes wrong in our lives when often he has no direct part in it. Might I suggest that a more plausible diagnosis of your problem is a mental health issue? Please, get it checked out by a visit to your GP, if it comes back OK, then what have you lost? Science tells us that the majority of mental health issues result from chemical or hormone imbalances and pretty much all medical opinion categorises mental health issues as just another chronic condition that for the greater part is manageable by therapies and medication in much the same way as diabetes, asthma, heart conditions and arthritis.
Therefore can I please implore that you get your mental health checked out urgently, these things don't usually get better with time, rather worse so early intervention is a big plus? Meantime, please don't give Satan any more glory claiming that he's wounded and is now in control of one of Jesus's precious sisters, he isn't, but instead, through the haze look to God, seek more and more of His Holy Spirit's blessings and give God thanks, praise and adoration. That's not as easy as it sounds when you're in despair but I believe that to God praise when you're in that situation is as precious to Him as the widow's mite (Luke 21:1-4). So start with thank you God for (long list) and then what I love about you God is (another long list) moving onto, you're wonderful and amazing because (longer list still).
So try to relax in God's loving care, try to distinguish between wonky thoughts (like demons are in control of you) and normal logical thoughts and try to archive and ignore the former. Constant prayer and constant praise is your route out of this situation. Hold onto Jesus's promise in John 10:27-30.
God bless you sweet li'l sis and may today be Spirit filled and blessings stuffed day for you.
Lots and lots of love, Andy xx