Dipenhydramine-based sleep-aids are the main otc products for this (Nytol, Sominex etc or just cheap generics at a fraction of the price) they're quite effective at the right dose (50mgs is a good sedative dose)
If you suffer from depression as well as sleep troubles, I'd say asking your doctor for mirtazipine would be a good idea, it's a great anti-depressant and also a fairly powerful sleep aid with no hangover. (Be warned: it's a powerful appetite enhancer, and many people have gained weight)
Some Benzo's are very effective sedatives, but no good for your condition; this sounds like a long term thing, and these drugs are very addictive within weeks, with nasty withdrawals.
There are some surprisingly effective herbal sleep aids on the market; Nytol make one which is fairly effective. Also, valerian and kava can work well with the right doses, as well as many others.
Obviously, you want to avoid caffeine at all costs. Coffee has a rather high amount of caffeine, and the effects last for longer than you might think. Also, engage in restful activities before your regular bed time; avoid exercise ( it gets your endorphin levels pumped up. Avoid sugary foods, and fruits (fruit is loaded with natural sugars)
Use a combination of these suggestions, and I think you'll be okay. I was in the same boat as you, and now have no problem with this.
