You don't like pills, why, because they are drugs? Well guess what, you're addicted to sugar. Your body has adapted to operate on the high levels of caffeine, but the high levels of sugar make you blood-sugar rise, creating the sleepiness. You are addicted to a white substance, and can't function without it, yet you're scared of Tylenol?
You probably had your change in sleep because you were still going through puberty, the body changes, your life changes, you schedule gets more hectic, sleep can get compromised. There is a myriad of tips I would give you, if you would listen, but I wonder if it's just a waste of my time. How is drugs like Acetaminophen so much worse than high fructose corn syrup?