I have questions about SATs.

1 - I believe Neville Goddard suggests falling asleep while practicing SATS, but I can't seem to manage it. I lie on my back; last night, I looped the scene for two hours—stopping and restarting twice—but I just couldn't fall asleep. Eventually, I gave up, turned onto my right side, and drifted off. What could the problem be?

2 - Should visualization only be done at night while falling asleep? Would doing it during the day whenever I have free time cause issues with the process? Or should I be thinking, "If I already possess it, why would I need to do it?"