Are you taking advantage of the food journal? If not I would start by not restricting the number of calories but by getting 'better' calories. My baby is even younger than yours, so I can't diet, but I am making myself get my calories from, for example, nuts and cheese instead of chocolate and ice cream. I have seen minimum calorie suggestions ranging from 1800 calories to 2500 calories per day, and I am struggling to hit 1800 calories a day without resorting to comfort foods. It would be easier, I suppose, if I liked healthy food more.
I can't imagine that exercise could be harmful for your baby.
My insurance company actually had a dietician call me today when I posed a similar question to them. Your insurance company may have a similar benefit. Couldn't hurt to ask.