i have had severe insomnia problems since a baby because of my autism,id go days without sleep-i was a living zombie.
doctors had always refused to help until i met a sympathetic GP who said he would prescribe me a month of circadin [AKA melatonin] and my then pyschiatrist made it a permenent script, it was a godsend but i got took off it when i got sectioned in a hospital and was put on the sedative zopiclone instead which sucks,i got took off it before leaving the hospital so i was once again left incredibly insomniaced.
when i asked to be put back on it,they told me the licence of the drug had been changed to only be for under 18s.

the only other thing besides alcohol that has helped me sleep is my anti pyschotic medication, haloperidol as it takes away my anxieties.

you could try yoga,mindfullness,deep breathing exercises,and sleep hygeine,these are all said to help for sleep issues but not for everyone,they dont for me.