Based on what I have heard from a Sleep Doctor (yes they exist). You should go to sleep at the same time every night and then wake up to bright light in the morning. You need about 10,000 lumens for around 10 min every morning for about two weeks, light boxes work the best but they are spendy. If it happens to be sunny when you wake up just go outside for a few minutes, that should help. Other than that, don't drink caffeine (it will keep you from sleeping well at night) and drink plenty of water.
Your sleep cycle is reset naturally by your body every two weeks, so if you can maintain a good schedule for about two weeks straight you should get back to square one with your sleep cycle. If you need help sleeping ask your doctor about Ambien. It puts you to sleep in about 15min and only keeps you asleep for about 1-2 hours so you sleep natually the rest of the time. I took it for awhile and it worked great for me.
SL