Look into this, it may be what you have.
Circadian Rhythm Disorder (light therapy was recommended to balance the natural hormones that affect the sleep.)
Delayed Sleep Phase Syndrome (DSPS)
The cause of DSPS is unknown, it is believed to be a disorder of the body's timing system. These persons have difficulty falling asleep and difficulty waking because their biological clocks are out of phase with the sleeping and waking times they try to carry out. DSPS is therefore very similar to jet lag, but much longer-lasting. It can develop suddenly or gradually.
Vitamin B12 from sleep disorders has shown to be helpful.
There have been a wide range of treatments techniques used most with varying degrees of success.
These include Bright Light Therapy, Chronotherapy, other treatments mentioned were controversial.
Five Element Acupuncture is an ancient form of acupuncture that works by treating a person at the levels of body, mind, heart and spirit. By doing this it helps a person move back into harmony with themselves, their emotions and their life as a whole."
Biofeedback & Bio/Neurofeedback is a technique that is based on the fact that one can activate systematically the natural mending(healing) processes of the body.
How much early sunlight do you get? Do you think this may be your problem? I hope I've shed some light
on what your looking for. Diana