I remember in the immediate aftermath of a previous surgery I had around 12 years ago(my most serious one) I had insomnia for like 2 weeks and it wasn't from pain cuz I had pain meds. I tried warm milk. I don't know if it really helps you sleep because it tastes nasty and I poured it out after 1 sip. I was desperate for sleep at that point too, but I couldn't imagine drinking an entire glass or even half a glass.
Maybe try that sleepytime tea with the bear on the cover. Tee hee he's got pajama's on. If it doesn't help you sleep it will at least calm you a bit.