The "scientific" answer to what you should eat is this:
Breads/Starches = 4-6 servings per day
Protein = 4 servings per day
Dairy = 4-6 servings per day
Fat = 3 servings per day
Fruit = 3-4 servings per day
Veg = 3-4 servings per day.

That looks like a lot of food! but keep in mind that the serving sizes are not that big.

I think eat sensibly. I also eat a lot, but I always ask myself just one question. "Could I make a heathier choice than what I am about to put into my mouth?" For example, yesterday, I was very thirsty whilst out shopping. I picked up a coke, then asked myself the question. I replaced it with a bottled water and a small juice.

With regards to Low GI. They are better.
Try brown rice instead of white
Health/wholewheat bread instead of white
Peas and carrots are high GI, but good for you, so include them in small quantities.

But, if you feel like you have to have a chocolate, then have it! Your baby wants it, and what the hell, you deserve to spoil yourself!