I've been looking all over the site for a description/explanation of a feeling i have when I transition into a dream, but can't find anything. It's like I am entering a portal, but i am being sucked through it at an extremely high velocity and its almost crushing. Its like every part of my body is under a giant vacuum cleaner, and it feels hard to breathe, although im not sure if i'm actually dreaming at this point and breathing is not entirely necessary. There is always very loud siren-like sounds, and my visual field consists of something like you would see on a TV filled with static signals, but much more colorful. This usually lasts about 10 seconds (which are generally very unpleasant to endure), but after the sucking sensation goes away, i kind of "roll over" and feel like im tumbling down through space, and then I open my eyes and i'm in a dream.

Is there a name for this phenomenon? I can't seem to find any descriptions of this experience which leads me to believe maybe its just my own personal "transition" into the dream state, but I feel like i cant be the only one who experiences this. Anyone ever go through this kind of thing?