Yup, chocolate/sugar/caffeine will make you more awake. That's the problem. At least for me, these all will either make it impossible for me to fall asleep (if I eat them too late in the evening) - or disturb my sleep (I don't reach a deep level of sleep and am restless in the night) if I have them early in the day.

It's worth trying to eliminate sugar/chocolate/caffeine for some time (maybe a minimum of 2 weeks, more is better) to see if you notice a difference. It's pretty rotten, b/c I love chocolate too - and have just started eating it too many days in a row again to deal with stress - but for me it NOTICEABLY affects my sleep. When I've been eating chocolate... it takes like 3-5 days of NO chocolate to get back to normal sleep! Seriously, it takes that long for my brain to get "back to normal". But the difference is amazing.

re: The light... right, but you need to avoid blue light *before* bed too. So, if I want to go to bed at midnight, I turn out ALL the regular lights, tvs, phones, computer screens, tablets, etc by 10pm or 10:30... so that I get 1.5-2 hours with no blue light before bed. That way your brain can make melatonin. It makes it much easier to fall asleep (as long as I'm avoiding sugar - sugar screws this up for me.) Just use orange lightbulbs instead of regular white ones.

It's been insanely helpful for me... as I said... I was chronically exhausted before, and was pretty convinced that I was going down the road of "chronic fatigue". All pretty cheap solutions too... though giving up chocolate is not easy

good luck!