How to fall asleep early? I think I might have a circadian rhythm disorder?

I usually go to sleep at 10PM and actually end up fall asleep until 12PM, and end up waking up at 5:30, so I know what you mean. Lately what I have been doing is keeping away from caffinated drinks or overall high sugar containing drinks or food after 3 PM. I have also been running 2 miles four times a week around 8PM-9PM...this workout leaves me stress free and weary so I end up going to sleep quite after my run. I do recommend purchasing melatonin supplements, which you can buy at a supplemental store or maybe at Walmart. A multi vitamin with the melatonin supplement also won't not hurt. This routine seems to be helping me alot. Hope I helped you out..