Do I eat too much in a day?

I would say this isn't enough nutrition for one day, especially since you don't really exercise. Exercising can cause you to eat more because you are using more energy, so this can help tone your body and grow. I am younger than you and I eat alot more! You didn't include your weight, but I think you should incorporate a little more food into your diet, but still healthy foods, such as tofu, brown rice, pasta, fruits, etc.