Serotonin helps you sleep, which is why even after taking pure MDMA, you may still have problems sleeping. If you are taking untested pills, and have a real hard time sleeping, you probably got a methbomb or piped. Nonetheless, take 100mg of 5-HTP and you should be able to sleep better. Weed/Benzos/Alcohol also help. Eat little things the next day, maybe like some fruit, then later maybe a peanut butter sandwich, then lastly yogurt or something. Instead of eating a couple large meals, eat small meals, when you feel like your body would naturally be hungry (if you lack an appetite).