thats one helluvasleep disorder you have! have you been to the docs about it..there are things that help....
Circadian rhythm disorders
Exogenous melatonin taken in the evening is, together with light therapy upon awakening, the standard treatment for delayed sleep phase syndrome (DSPS) and non-24-hour sleep-wake syndrome. It appears to have some use against other circadian rhythm sleep disorders as well, such as jet lag and the problems of people who work rotating or night shifts. Melatonin reduces sleep onset latency to a greater extent in people with DSPS than in people with insomnia.[17]
Taken 30 to 90 minutes before bedtime, melatonin supplementation acts as a mild hypnotic. It causes melatonin levels in the blood to rise earlier than the brain's own production accomplishes. This usage is now common in sleep and relaxation drinks.[18]
A very small dose taken several hours before bedtime in accordance with the phase response curve for melatonin in humans (PRC) doesn't cause sleepiness but, acting as a chronobiotic (affecting aspects of biological time structure),[19] advances the phase slightly and is additive to the effect of using light therapy upon awakening. Light therapy may advance the phase about one to two-and-a-half hours and a small oral dose of melatonin, timed correctly some hours before bedtime, can add about 30 minutes to the advance achieved with light therapy.[20]