Did you work around the clock? I've read that some people really utilise 'short sleeps' when coming off night shifts - basically only sleeping for a few hours, powering through the rest of the day and then sleep at night to reset the body clock (as much as possible).
I only did night shifts but I always tried to keep the body in sync with my working hours, trying to adjust the body clock back to normal hours was very hard for me so i usually stayed in tune with the hours i work. It's hard for the body to settle down and sleep straight away after a shift, especially when you are driving home as the sun comes up!
Try and make your bedroom as dark as possible during the day when sleeping and some 'white noise' can be good so you don't get woken up by outside noise like doors shutting and cars driving past.
At the start sleep will feel like a must but once i had done a few years i got use to working shifts on minimal sleep, it's all about getting past that wall you will hit at work, once the body learns to get past it then you won't be as anxious about working if you didn't get as much sleep as you wanted.
I think every new person I worked with hit that flat spot 2 or 3 weeks in where they really hated it but stay positive as the longer you do it the easier it will become.