Not sure if astral projection...

On nights where I go to sleep and wake up a few hours later, right before I go back to sleep I get this intense vibrating/buzzing sensation throughout my whole body. When this hits it's peak, I can pull myself out of my physical form and float around my room, usually through the chakra in my throat. But that's about the farthest I can get; I can't get out of the door or the window, I'm stuck in my room. When I float through my ceiling I come back through the floor and when I go through my floor I just fall into blackness and then enter a dream. Also, when I'm completely separated I am still very very sluggish, it takes a lot of effort to move myself around. Could anyone explain to me what is happening, I've read throughout some of the stickies and other people's posts (new user here) but there wasn't anything I could find describing whether this was astral projection or not. Thanks.