Rose,
I still struggle with sugar, especially chocolate. However, I lost most of my weight while working at McDonald's, so I do have a few tips I can share with you
First, make sure you have access to a satisfying, tasty, healthy lunch every day. Then, make ALL treats at the bakery OFF limits and bring your own (healthy) treats to work. I used to think that I was addicted to McDonald's icecream, and I traded it for one or two fat-free fruit yogurts a day.
If you really like something at work, maybe treat yourself to that one item on your day off. The fact that you have to purchase it (I'm presuming it's only free on days that you work) and that others are aware of it will prevent it from becoming a binge.
You can do this! If you need any support or have any questions, msg me!