Have you had your vitamin D levels tested? Since you work at night, you're probably not seeing a whole lot of sunshine, so you may be low & vitamin D deficiencies have been linked to poor sleep. It's worth a try. Also, people hate hearing this one, but are you getting enough exercise? 30 minutes of moderate exercise during the day (or rather, your awake time) can make a world of difference in your ability to sleep. It can be broken up, too. 10 minutes brisk walk before work, 10 minutes on a break, and 10 minutes when you get off...Better yet, don't you have a young son? A good old wrestling match would certainly count as moderate to vigorous exercise, depending on the boy.
You could count that for a 10 minute session. Or am I confusing you with someone else? Sorry if I am!