Hi,
Ironically, my career has been the other way round! I started off in retail (for over 20 years) and have now progressed to an office based job. I've only been recently diagnosed, so have no idea what effect 'retail' has on diabetes.
However, I think you should really think this through. In retail, 7 day working is not as much fun as its made out to be! The hours can be very long, espeacially coming up to Christmas. I often started at 7am and finished up to midnight. In addition, I have actually worked many Christmas days - who do you think prepares the sales for boxing day!
You are also very much in the hands of the general public, meal breaks etc are determined by how busy the store is - rather than rigid times. In an office, things like this can be more regimented, and I would assume easier to manage your diabetes. If you are operating a till, or in the middle of a long sale, you can't really leave to blood test & inject.
It took me a year to get use to an 'office' lifestyle, for a start, I had every weekend off. As for Christmas, it was a total shock to my system that I actually had time off and instead of workload ramping up, it actually decreased. I know you are looking for a change, but the grass is always greener.......
Stephen