Toddler Weight

I should be losing weight.
Prior to getting pregnant I wanted to lose some weight so I would be healthy and not have as much to shed after the baby was delivered.  This was done fairly easily, and continued as morning sickeness hit.  I even excercised on occassion, and continued to walk up and down the stairs at work at least twice a day until about my last month when I got winded easily.  I'd still walk down most of the time because I knew with my luck I'd be stuck in the elevator during delivery.  It would have made for a great birth story, but I did not relish the thought of any of my coworkers delivering my first-born.
Due mostly to luck, I'm sure, and the fact that I breastfed, I lost the baby weight in a month or so.  Unfortunately, since then I've gained it back, and then some.  Now the question is, how in the world did this happen?  Any stay-at-home-mother knows that she never has time to eat, let alone make, a nutritious and filling meal, and often times "sleep trumps eats" when the baby does nap on his own.  Now that DD feeds herself, I have more time to actually enjoy my meal...usually.  However, DD enjoys eating whatever I am, often straight off my plate, which means I have less food to eat, therefore I should be losing weight.  However, there are times when she wants something different, but then does not finish her meal, so guess who does?  Plus, making a second meal, or snacking on junk food due to hunger since DD ate my first meal, surely does not help matters.  Yes, she's constantly running around, which means I'm often running after her, but lately I've been running as little as possible.
My goal, by May, is to rid the house of junk and snack foods so I'm not tempted, and DD isn't begging me for "caycay."  I'll make us Ants on a Log for snacks, not get seconds when she finishes my meals, and eat more fruits for dessert.  I'll also do my best to drive past McDonald's instead of treating myself to a McFlurry for being a "good girl."  I guess I should exercise more, too, huh?