i have a fuckload of trouble with sleep too. i haven't really experimented much with things like diet etc to remedy this, but i personally find that the best thing to do is to go about my day with the single goal of being completely drained by its conclusion. if i'm exhausted by the time i go to bed, the day has been successful. i seem to feel far more refreshed and rejuvenated the next day if i do this.

that said, you seem to be pretty active physically (compared to me at least), and you don't have any trouble getting to sleep (which i do in a big way), so, in all likelihood, yours is a completely different problem to mine but hey, maybe this will help in some small way. GL.