A "quick fix" solution worth trying is to avoid using your computer within several hours of your bedtime.
Computer screens give off a blue-toned light that mimics the wavelength of morning light, and could possibly trick your brain into turning off production of melatonin, the "sleepiness hormone" that is normally produced at night.
There has been interesting research done lately on how various colors of light affect our circadian rhythms. Here's a link:
Science News