First of all, give yourself a little break as far as kicking yourself! True children get frightened of these scary images and perhaps you might not have taken him if you had considered this, but we all make mistakes and no real harm done! Take a deep breath and remind yourself that you're a great mom! I think you can turn this into a great learning experience for your son, and maybe you as well. I have a friend who began mindfulness meditaton, on her own, when she was about five. It's never to early to teach these techniques. You might try taking to your son about the value of quieting the mind for situations Iike this- something nagging at your brain keeping you up, whether it's disturbing images, a conflict that happened earlier in the day at school, or having trouble winding down from an exciting day. One technique I particularly like that can work well with children is seeing your mind as a wheel, with thoughts out on the rim - good thoughts, bad thoughts, scary images, whatever, and realizing that you are at the center of the wheel. Dr. Dan Siegel is a child psychiatrist and if you look him up with "wheel of awareness" and "children" you can find more info about this. Good luck!