Well, when we are busy we tend to grab whatever is nearby and eat that to save time. So, make sure your office is full of healthy go to snacks already packaged in one serving sizes that way it will be a little harder to overeat. Exercise is probably hard, but try to get up and walk or jog around your office every few hours at least. It also might make you more productive because exercise can help you focus.
I also have a busy season, but it involves travel and so I had to find a healthy way to eat in the car. Unfortunately, I usually tend to not eat when I am busy and that isn't good either.
Good luck! Loose it now and then you only have to maintain during your next busy season so it might be a little easier.
Tomorrow is fresh with no mistakes in it.