Indiana, I highly recommend this site:
http://bloodsugar101.com/. Also, I recommend Jenny Ruhl's book,
Blood Sugar 101. It's a common misperception that people with blood sugar problems get their diabetes from overeating, when in fact their problems metabolizing glucose contribute to their overweight.
Let's face it, since Earl Butz changed the US Government's attitudes towards grains, especially corn, and all their sugar-laden byproducts, most people have jumped on the high carb, low fat (HCLF) bandwagon. This is fine for people without blood sugar problems, but a disaster for those with them. Most docs are also recommending the same diet to everyone, and add statins to the mix to mitigate non-existent cholesterol "problems."
Since you're a diabetic, you're probably already used to testing yourself. The whole approach used by Ruhl is to measure your blood 1 hour and 2 hours after your favorite meals, and develop a diet that is customized to YOU, based on avoiding the foods that cause your blood sugar to spike beyond 140. For some people, that means a ketogenic diet; others can handle 100 gm. or even 125 gm. of carbs per day. The most important thing is to avoid the really high spikes, i.e., anything above 140. That's when the damage occurs.
It would have been interesting to measure your blood sugar after that pizza, chicken nuggets, and chips dinner. I bet it was in the 160 to 180 range. It's no wonder you got depressed after that -- not because you screwed up, but because your body's inability to process all that sugar wreaked havoc with your sugar levels, causing you to be depressed and yes, ravenous for even more sugar.
Too often, people with blood sugar problems think it's just a matter of their "attitude," when in fact they have no clue what's happening to their metabolism because of their out of control blood sugar levels. Insofar as it is "attitude" it's a matter of doing some research and discovering what you can and can't eat in order to keep your sugar under control -- and that's a matter of understanding the mechanisms of glucose metabolism and then testing, testing, testing -- until you come up with a way of eating you can stick with the rest of your life.