Strange experiences. What could it be?

Before i start let me just tell you that i neither believe nor disbelieve in the paranormal. I've had experiences of my own but cannot conclusively say either way whether it was real, imagined or something else.

To fill you in, i used to be quite into the spiritual scene

Ok, here is what has been happening somewhat frequently over the past 3ish months.

At night i have been experiencing Astral projection type sensations but not exactly like i have felt before. This feels more like being replaced in my mind rather than leaving the body(which i never fully attained before). This is quite difficult to describe but i will do my best.

After the "vibrations" which is more of a intense pulse that i can control i suddenly become nothing, which is to say i have no body, its as if im a "thought" only, but i can see. I seem to be hovering high over a vast mountain range, only the mountains also have no depth. At this point i start to feel a pulling sensation, tugging at what i can only guess is my mind. I try to fight the pull but the force pulls harder until i suddenly "blip" and the pull has gone. The cycle of being pulled continues on until i finally hold my self against the pull. At this stage the scene changes to a blank void with what i see as another mind, although i sense rather than see. This mind tells me that i have gained another essence of raised acheivement. This is where i always wake up.

This used to happen to me many years ago but only when i was unwell and i never got past the point of holding off against the pull. I have no idea what this is and would appreciate your views. Is it paranormal interference? is it just my imagination or do you have any other ideas?