You have my deepest sympathy. For the past 2 and a half years I've suffered with dreadful insomnia brought on by various pains in the last 4 months of my pregnancy, and then by having a baby with stomach problems who would wake between 10 and 30 times a night. It's only starting to improve now because I'm closing watching my dd's diet so she sleeps better.
What I have abused on a regular, but temporary basis, is Benylin Original. The drowsy one ! One tablespoon has always managed to get me back to sleep, and it doesn't give me any type of woolly head the next day.
You just need something to break the cycle, but obviously "good old anxiety issues" are probably the root cause. Go to your doctor if this is the case and ask for CBT.