As-salamu alaykum sister,
Working and fasting can be a challenge, especially when we must meet with others and be alert, cheerful and appear not fatigued. Often as our bodies adjust to the fasting, we can get energized as our body adjusts to the new schedule of fasting in the day and nourishment at night and before fajr. Try to eat protein and carb rich foods to get you through the day as well as rinse your face with cool fresh water periodically to refresh yourself in the day. As your boss and coworkers know you’re Muslim, it wouldn’t hurt to let them know you are fasting. I am not sure of your relationship with them, however if they are supportive they will be more understanding. It is best though to not let our fasting have a negative effect on our work, though it is sometimes hard! Give your body a few days to adjust sister, and make duaa to Allah to grant you ease during this most blessed month. Remember you are not alone in this work-fasting dilemma, and all too soon, Ramadan will be over so fast and we will miss it!