I am a long-suffering insomniac and have pretty much tried everything (ok, not lettuce). I do resort to over the counter antihistamines (blue box, take two a night, but I can only take one or I can't think) very occasionally despite their being criticised by medics as one up from crack cocaine. They do work when you are desperate. It is really odd because I cannot and will not take any 'mind altering' painkillers (codeine) because they send me into a hazy stupor, and am violently allergic to morphine, which sends me unconscious after several hours of vomiting, so jolly well ought to sleep like a cat (was going to say baby, but babies are rubbish sleepers until you train them!). But no.
A fellow sufferer and close friend of mine, a great thinker and brilliant woman whose achievements I can only dream of, was told by her doctor that it is the fate of the highly intelligent. So just go with that one, countrymum...tell yourself it is the burden of supreme intelligence. It is small comfort at 3am, and I always think I could be so much more if only I slept like other people do, but maybe the world isn't ready for us yet!