I have the same issue. For it I take 2mg of klonopin 30 minutes before taking my sleeping pill (Lunesta). I have other sleep issues, like waking up in the middle of the night wide awake unable to go back to sleep until late morning, but that at least gets me to sleep.

I also don't make this recommendation lightly, as every doctor will tell you it is horrible sleep hygiene, but if I'm really worked up (like the first week in a new apartment, or when living with my parents and they go on vacation) I'll go to sleep with music or the tv on to distract my mind.