(Not a question.)
It's FANTASTIC that you are already avoiding other food temptations by bringing your lunch.
Now you have a perfect way to level up.
The time you give yourself is just as important as the food. What do you do during this break besides eat? Nourish the whole you. If you're not already, do something active in the world--even for just 15 minutes--that really feels like YOU. Think of it as a little oasis of happiness. Or not. But that's kinda the idea.
Also, Box Lunch Lifestyle is a lifestyle, and that includes paying attention to what you like and don't like--and doing something about it. For example, how much energy do you have around 3 p.m.? A slump could be related to your lunch food (or time!) choices. A better lunch should help you feel good all day, so keep checking to see when it's time for a tweak, or an overhaul.