bravo on trying to improve your fitness! too many of us are stagnate.
Nutrition while trying to lose weight and intense workouts do not always go hand in hand.
Carbs are good for workouts but worthless for sitting at a desk or on the couch. If you are trying to lose weight you may not have the best metabolism so you have to manipulate it.
Try to plug in two workouts a day, they dont have to all be busters, but just get that heartrate up more often. Also, keep the carbs on the lowdown except for about two hours before class. and make them dark carbs, not white. I call white carbs everything that tasts good. like sugar. cookies, cake icecream.
Easy on the serving size. (my own worst enemy) Eat slower and smaller. The slower helps the smaller seem bigger. and more meals....breakfast, lunch and dinner smaller, and the snacks a bit larger.
You may very well notice that you dont have the same energy level in class trying to lose weight. Finding the happy medium is tough and different for everyone.
just some things that have helped me.