I also had this kind of dream when I was a child.
THey stopped when I was 16
I also felt that the "entity" will suck my life, or my identity.
I was very strong and was able to run and run and it never got me.
But I was very scared of it and was aware of the evil purpose of getting my life, or my mind.
I think I overcame conciously it by thinking about it when I was awake and rejecting it and declaring it had no power over me.
Now I am christian. Your post remained me that I need to pray.
I feel now that it was an indication of the challenges I would face in my life, and I need to pray and ask God for guidance and protection since those dreams were more like a real experience than just a dream.
But I do not feel scared anymore and I know Jesus has given me the autority to reject those devil dreams.
I remember I used to pray in my dream while runnig. Maybe it is why I was so strong.