Maybe I can help. I have been trying to astral project for about a month now, and I haven't been successful but I do know quite a bit about the subject because I've read books and talked to people who have experienced it. One thing that I have come across in trying to do this, is my dreams are becoming more and more clear. When you astral project (again, this info is not personal experience but has been told to me) you do not see things that you are exactly accustomed to seeing (like the nurse you saw).
Here is what I suspect you are experiencing; and I think this because I am in the same place as well. You are very close, but you're in a mental projection/lucid dream state. For me, there was a series of nights where my dreams had a similar theme to them. In all of them I was trying to have a lucid dream, basically in each one I was approached by something that I feared (first I was in the ocean and it became shark infested, second was a deranged man chasing me, and third was some Russian that wanted to kill me...I'm not afraid of Russians..Anways--) and at some point I realized I was dreaming. From there I would make something happen to counter the fear (for the sharks i made a ship appear, for the man I got into a car, and the Russian guy (if you watch Dexter) was taken care of in the same manner Dexter would handle it).
After escaping the fear and partially entering a lucid dream, the fear itself would overpower whatever I threw at it, wold conquer me, and I would wake up. I took from this that I had a mental block somewhere, or some kind of fear that was keeping me from astral projecting. I would see if you can find some pattern as well. Astral projecting can be an amazing experience, but you need to be mentally strong and capable once you get up there. There are entities who wait for you right as you leave your body; however these are nothing to fear as long as you don't be fear or low vibrations with you as you project. Low vibration entities are mindless, they're leeches that just want energy. It only takes the wave of a finger to send them scampering away, but you have to have the mind for it. Hope this helps!
Edited by RedNova, 16 March 2013 - 05:05 AM.