There nothing like floating above your body in your astral body while looking down on your body laying in the bed.

And although it may not be the easiest thing to accomplish, it is much easier once your body reaches the state you've described of being very heavy and unable to move.

Simply concentrate on floating and being above your body, or concentrate as intently as you can on your third eye, and see what happens. If you are lucky enough you will find yourself outside of your body, and very aware of what is going on, having an experience every bit as incredible as a lucid dream.