Ahh, the intro says it all.
How, in the world, can I be GAINING weight while I am nursing? Let's see, maybe this has everything to do with it: I am simply eating too much, at the wrong times, and the wrong things. I am CRAVING sugar, all the time - I've never done this before, it's so strange.

I need help - I have never weighed this much in my life!
Any ideas on how to start?

When I was nursing my children I made sure I ate a well balanced diet. Nursing does not keep one from gaining weight. It really is calories in and calories out. Back then I was staying within the same calorie range I am staying in now. Take a look at what you are eating. Fit day is a great free site to use to do this. You might find you are eating more than you think you are. Make sure you are eating a well balanced diet. Required amounts of the four basic food groups is a great place to start. I bet once you get what you are eating in order you will see the weight start to come off.

Refined sugar/carbs are evil in my book. When you are breastfeeding you have to make sure you drink A LOT of water. I craved sugary foods too when I was breastfeeding. Turns out I was just thirsty. Drink water before you eat and after you eat to make sure you are well hydrated. Also the less you eat that sugary stuff the less you crave. It's the first week or so of getting off the refined stuff that is tough but after that it gets easier.