Well you are certainly not alone! Fear & paranoia & worry are all things I have experienced and many others I'm sure.
After being a Christian a long time I have only relatively recently understood the peace and freedom from those things that we have in Jesus - but just need to take hold of.
Fill your mind with Jesus' teaching and with Christian music (if you aren't in to listening to praise music then you can find a Christian contemporary artist) it is SO HELPFUL I find

!
Don't worry about the weird images - I was really helped by CS lewis (I think) who said that when he has thoughts that worry him, he just gives them to God rather than dwell on them.
The more you think and worry about the fearful things & the images - the weaker your faith will feel.
It's not easy but ....give praise to God for what you KNOW to be true. Literally what you do believe, however little it seems to be at times. Even if it's just that Jesus died & rose for you - or that Jesus loves you.
The more I focus and praise in this way -not in a desperate talking-myself-into-it-type way (which I used to find myself doing) - the more I understand it in a profound way.
But if I stop I still get negged out or overwhelmed by life or sometimes by old fears.
You know all the Positive thinking teaching there is out there for businesses and people in general Well it's a bit like that - but because of the profound & spiritual truth in the things you are telling yourself from the bible - it's much better and stronger
I hope I haven't wittered on too much - I have really been freed from strong fear & anxiety that I didn't realise I had my whole life because I was so used to it - even though I'd been a Christian; but - like Romans 12 v 2 says - I'm realising it really is possible to be transformed from that, by the renewing of my mind - i.e. by dwelling on the truths about God and who He is and what He promised and his love for you.!
p.s.
(It's going to be a good thing that you read the Qu'ran because it will help you understand things that many British Muslim people are being taught.)