I had chronic insomnia for years throughout highschool, at the time regardless of exercise, relaxation, diet, I couldn't get over it. Really it was just one of those things that, over time, kind of went away on its own. Melatonin pills can help a lot, I still take one every now and then if I have a hard time falling asleep. The other great medication for insomnia that I have found is muscle relaxers, i.e. cyclobenzaprine(flexeril) or carisoprodol(somas). Muscle relaxers are really great for insomnia, at least they are for me, as they relax the body and can really help you fall asleep even if you just take them at night. They aren't narcotic like benzodiazepenes(xanax etc.) or painkillers or anything like that, so I have been to take them for years on and off without any dependency problems or physical side effects whatsoever. Oh and by the way fuck Ambien, that shit gives roughly 5-10% of the people who take it severe hallucinations, myself included, which is a side effect that they didn't even officially start listing until about five years ago.