These shadows feed off of fear. So you have to find it in you to turn around and not run from them. They keep coming to you because you run.
Christians believe that their God is more powerful than anything and nothing harm them in his care right? So use that in your dream.
Somehow your fear is making you forget your strengths and that is that you are protected under Gods love (according to my husband and Christian friends).
Here is what I know to be fact...
Growing up and well into my early thirties I had the same dreams and the same fears. I would wake up and feel them holding me down.
My husband would tell me..I have the power to stop it all, I just have to believe in myself and my abilities and turn around and face it"
So one night...in my dream..again..I was being chased by these "demons" and it reached out to grab me like it always did, and I just snapped! I had enough! I was tired of not being able to sleep peacefully and being tormented, so I screamed as loud as I could.."STOP!!!" and opened my hand and shot white light out at it.
It screamed and disappeared. I'm not going to lie and tell you that it didn't try a time or two again. But this time I was prepared.
This caused me to look into what this light was and what it meant.
So here is what I know. That white light is called "Divine Light". You can attribute it to whatever deity you choose...the Christian God..the Goddess.. Whomever you choose, it comes from the same place and the bottom line is, it hurts those shadow people/demons/negative entities. They can't stand it.
So at night before bed, surround yourself in an egg of white light and practice visualizing yourself shooting it out of your hand like Spider-Man is how one of my teachers told me when I first started learning.
You will eventually learn not to be afraid and they will know that you are no longer a food/energy source for them.
I hope this helps. I have never shared this publicly as I am aware of how it sounds, but I didn't want you to feel alone. There is an end if you take back your power. :)