Invest in blackout curtains for your bedroom and ensure no light is seen around them. Set a strict sleep schedule, i.e I come home, eat, allow myself three hours to unwind then go to bed. If possible stick to as close to your work schedule on your days off as possible at least for the first month. Try to avoid the urge to eat too much junk food. It's common for people to grave salt and sugar through the night but this is not only unhealthy but will also make it harder to get good sleep.