Aylaine said:
Try to find your sleep niche. For me, it's doing something that relaxes me before bed, then sleeping with the fan on. Stillness in the air will prevent me from sleeping normally, but the humming sound of the fan soothes me and it actually puts me to sleep faster then anything else besides my girlfriend. Just little things like that could make all the difference. Try sleeping with a fan, and before that doing a relaxing activity.
Additionally, and this is meant to be a serious recommendation, you could try masturbation. Sexual climax is extremely relaxing, at least to the people I've talked to and been with, and aside from a fan that will put me in that relaxed mood to sleep in a jiffy. You could try this as well.
I hope this helps!
Classic solution of white noise with that fan approach, however your suggestion of masturbation might not be so nail on the head, studies show that unlike climax from intercourse, masturbation produces very little in the way of a natural tiredness/sleep response.
alternativly Ecky, you could should the issue really get to you, see a doctor, it depends for how long this has been going on. again be very sure that there's nothing bothering you at the moment that could be causing subconcious conflict wheter it be friendship issues, coming to terms with a death in the family (even if that death was awhile ago.) parental/sibling issues (you being aware of finnancial problems of someone close to you can induce sleep problems)
if the problem persists for more than a month continiously go to your GP, keep reporting back to him (it might take several attempts to get the right doseage) until you can sleep, continiously (without waking up, rolling over back to sleep.) through the night.
Good luck.