You are already astral projecting and returning to your physical body. What Erin wrote was correct and it does not mean you won't be able to return to your physical body. One thing to consider is that you are already astral projecting every time your physical body sleeps regardless of whether you remember dreams or not, but you are not conscious of these projections from and returns into the physical body.
So that experience you had was not a special astral projection or the first one, it was only the first conscious projection, with stress on the world conscious.
The system which keeps your physical body alive and which was operating the unconscious astral projections from the time of your birth, will be sure to return you to your body, just as it always did since you got this body.
For further reading and for methods of practicing, see my recent book:
https://sites.google.com/site/michae...tion-pictorial