Hi, there is a section on SR forums that deals specifically with insominia. Here is the link
Insomnia/Nightmares - SoberRecovery : Alcoholism Drug Addiction Help and Information
you might want to start by reading the "stickies" at the top of the page. There is one that has a list of ideas.
I have had long bouts of insomnia myself. I use antihistimines sometimes too.