Why is it so hard?

I have started trying to lose some weight, and it just seems to be extra hard. I feel like as soon as I decide that I am really going to watch it, all I can think about is food and treats. I have always found with each one of my babies that while I am nursing I just want to eat non-stop, well you can't do that and still lose weight, but yet I need to make sure and eat enough so that I don't lose my milk supply. It is really hard to find that happy medium and the self-control!! I wish there was a magic pill (that didn't cause heart problems- you all remember phen-phen).