Attempted a nap WILD today

I attempted to WILD in a nap.
It failed, but I'm not sure if I did it right or not. Here's what I did:

First I put on my headphones that usually block out most all noise, and started the "Naturespace app" (If you don't know what app that is, it's an app that plays really relaxing 3D like nature sounds) and configured it to run the same track for 45 minutes. I put on my blindfold thingy as well, to block out the light from my window. I layed down and started the music. For at least 30 minutes straight, I repeated over and over in my head the goals that I would do in order for that lucid dream. After each time I said all of the goals I would do in my head, I would kind of focus on the darkness, and say to myself "I am aware."

After those 30 minutes or so, I just let my mind wander. By this point, I wasn't even numb yet. I was freezing though. After a minute or so of letting my mind wander a couple of times, I said again, "I am aware." Then the music stopped. I guess the timer was up. I still wasn't completely numb or anything. I did the same routine again, letting my mind wander and saying "I am aware". I let my mind wander too much on accident, then fell asleep.

Why wasn't I able to "fall asleep" faster? Was I doing something wrong?

It could be that you weren't close to one of your REM periods. Did you wake up naturally or with an alarm clock? If you used an alarm clock then try setting it to a different time so that you have more or less sleep beforehand.