I read in a magazine a few weeks ago that you should try a breathing technique.
5 x deep breaths in (breathe out normally) followed by
7 x deep breaths out (breathe in normally)
I used to suffer from insomnia, and at beginning of pregnancy it started again .. until I tried this ... it really works! Haven't had problems sleeping since
I'm sure it wont work for everyone, but it's worth a go?