Who Are You? Why Are You Here In My Meditation?

I'm Christine and I made this account just to ask this.

Today I did a guided hypnosis meditation for the first time on ridding the subconscience of negativity.

Well, I while I was pretty much at the end of the session, I imagined myself opening my eyes to a black, tall skinny figure starring, standing over me, wearing a creepy mask.

It was terrifying and I knew it didn't have a face under the mask. This sent fright through my body. I don't know what it was.

Now, quick rewind, in the beginning of the mediation I envisioned myself holding the hands of something that was coming out of a pitch black door way (which represented my sub-conscience) asking it to please open itself, as it hugged me.

In the middle of my meditation I was in a realm where I was supposed to see my higher self, to which I saw a being made up of stars and cosmic dust who was massive... But there was something else... There was a being, skinny, tall and pitch black on top of a pyramid with a white circle on its head that had white light coming out of it.

This isn't my first time with this creature, I also had a dream with 5 of these beings (the tall black skinny ones) surrounding me when I was 7.

What is this thing?! Does anyone have any idea?

(I was also once warned that spirits act upon a different law than humans so sometimes if you come into contact with one their appearance can be frightening, but that doesn't mean its bad.)

I really need some answers. Should I be worried, or not? Is this my 'spirit guide', a manifestation of my negativity, or an unwanted friend?