I Want to Master Astral Projection.

I lay down, I'm completely relaxed. Thinking about nice simple things, then, my mind is empty. I can feel the energy as I focus on my breathing, it starts at my feet and makes its way up through my chakras as they open and finally the energy is all throughout my body, and seems to be building in my head. It feels like a ringing that gets louder and louder until its a train whistle right in my ear- crap. I open my eyes, i got nervous again right when I was gonna do it. Every time too. I almost get there, almost..