Dementor-like Entity

I'm very new to dream meanings, and they never concerned me until now. Please bear with me.

At least once a month, an entity seems to suck my energy/soul in a very similar manner to the Dementors from Harry Potter. Only their appearance is more like a humanoid ghost, that turns more and more white with each encounter. They have hollow "eyes" which are more like holes in their face, and the mouth is a sort of wispy looking opening with undefined "teeth". They simply hover over my bed where I lay. Nothing becomes cold or anything, however.

At first I thought it was just a dream. It still scared me a little so I tried to move. Somehow, as if my body was strapped down it was very hard to move. I managed to bury my face into my pillow and it somehow cut off the connection. When I am being drained, I feel only a hint of adrenaline and emptiness. I'd pass out as the entity gave up and faded and then wake up later. These instances only happen for 20 minutes on average and it's just as I drop off to sleep.

Once, I managed to move so much that I shoved my hand into its "mouth" and tossed it off my bed. I moved away from it first, but then decided to try and kick it, but it had long disappeared and I faded out.

More recently the entity had flattened my pillow and seemed to hold my wrists down, when I still managed to struggle from it, it suddenly let out a roar very much like a zombie cry. It's almost a glowing white now.

The days after being drained like this seem to have no effect on me. I don't feel exhausted, or anything but normal. But the fact the entity seems to be getting stronger concerns me, it seemed angry as well.

I hope this is enough, I remember the instances very clearly, so I'll answer questions best I can.

Sounds like sleep paralysis.

despite the entity?

I forgot to mention I did have sleep paralysis beforehand, often it felt more like I wasn't in control of my body.

I have had this many times and it can be terryfying, I would use a stronger word but there's not ne out there to describe it. It's sleep paralysis my friend. It can seem so real. Let me also say my SP comes on as I wake in the night and then I seem to be sucked into a vortex, the next minute I'm in my bed with this ghostly apparition attacking me, and I mean biting me etc and last time it happened it spoke to me for the first time ever and said "I will get you eventually, get out the fuckin duvet" then it bit my stomache. I woke in a blind sweat because even in normal dreams I sense it's presence, it's absolutely horrendous. When it happens again don't try to fight it, calm yourself and focus. Repeat to yourself "this is my dream and I'm in control" then ask it to "please leave". Trust me it works but it may take you a few times to manage to calm yourself enough. PM me anytime and ill help you with this. Good luck :)