I really feel for you- you sound just like me from a year ago

I gained 30lbs in my pregnancy, and the day I got home from the hospital, I only weighed 10lbs less than when I gave birth! WHAT!?! From there, the scale would not budge and in the winter time (my daughter was 4-6 months), I gained 6-7 lbs. And, I, too, had supply issues and simply refused to do anything drastic to my diet that might jeopardize my supply.
So, I decided that following the food pyramid (plus 300-500 calories extra since I was nursing) made the most sense for me since it was healthy, balanced, and why not? This way, I wasn't leaving any food group out. I didn't lose anything, but I didn't gain. At least I was eating much healthier.
I was a baking nut those first few months after giving birth, don't ask me why, I just was. Stress relief, perhaps (plus it produced comfort food!). Maybe that is where that winter weight came from ;-)
I felt hopeless that the scale did not budge downwards, even with restricting calories and walking several times a week at the mall. Hey, it helped all my girlfriends, so why not me? I still don't know the answer to that, but it just was.
The glimmer of hope in my story? I did lose 10 lbs around the 9 month mark. I have absolutely no idea how, but I did. I've read (I believe on kellymom.com-- not sure, sorry I don't have the exact reference) online that some women do experience an initial weight loss at around 9 months post-partum. Who knows, I was told breastfeeding would slim me down quickly, but it wasn't until afterward that I also heard it can also keep weight on you, too. I was obviously the latter.
Then, with 33 lbs more to lose to get down to my goal weight, I decided to do more than walking 5 days a week. Turns out, doing moderate/hard intensity exercise was way more of a benefit to me than low intensity. I continued to follow the food pyramid (since I'm still nursing I find no reason to cut anything healthy out). It is still hard, but on average I'm dropping 1 lb a week.
Now, mind you, the holidays have given me a major setback :-o But, I'm getting back into working out and dieting again. We all know how hard that can be. For me, it is all about getting back into the routine, kind of like jumping into a slow-moving cargo train.
I know I want to feed my daughter only healthy things, so I'm working on getting back into the mindset of eating only the foods I serve her. Makes sense, she's eating based off the food pyramid, too!
So, I was feeling just as helpless as you are now, and I'm only a few lbs away from my pre-pregnancy weight now (My daughter is 16 months). I've got 25 lbs to go now to be where I want to be. You should give yourself more credit- being a new mom is harder than anyone ever has the heart to tell you, and trying to find time for oneself to even think of deciding between working out or a nap is something one (at least me) wished they never took for granted before the baby. But, rest assured that things do get easier and time for yourself will come back again. The one thing you can control in all the new mommy madness is your diet. When you feel you're in control of that, you will feel loads better and even if you're not losing anything from that alone, take pride in the fact that you are healthier for the time being until you can devote more time to working out. Good luck, hang in there, don't be so hard on yourself and just enjoy being a mom to your beautiful baby.
Lizabell
P.S.- one last thing I didn't mention above: you've already gotten through a huge hurdle of losing the amount of weight that you did before you were pregnant, so it isn't like you can't do it (or know how to do it, you obviously know how to do it!). If your body is anything like mine was, it will take a while before the weight finally sheds. (BTW, when I lost the 10lbs at 9mo PP, my daughter was down to nursing only 2-3 times a day, and like I said, I did nothing at all to trigger that. The weight I've lost since then was all due to picking up my exercise pace and monitoring my calorie intake more carefully, even though I am still nursing.) Some women hold on to excess weight until they wean partially, or completely. By no means am I suggesting that, I am just saying that it is possible that it is awaiting you down the road!