I have to agree with eawright01 on this (at least somewhat).
I began having hypoglycemic episodes after the birth of my 3rd child two years ago. I found this page while researching ideas for healthy snacks several weeks ago.
I am a practicing supports manager and life coach and have come across clients who attribute symptoms of anxiety and depression to hypoglycemia and, even worse, the infamous "candidias ablicans," which generally only occurs in individuals with compromised immune systems (AIDS, chronic disease, ect.) and is easily diagnosed.
While my experience has given me an understanding of how rough this condition can be (when going long periods of time without a substantial meal or after consuming a carb-packed meal), many of the symptoms attributed to hypoglycemia are, in fact, caused by issues such as low serotonin, high cortisol, and the like.
There are many options, both natural and pharmacological, to address these issues. A healthy diet does help greatly (a diet too high in carbs does contribute to depression and sluggishness), but perhaps seeing a mental health specialist will give you the upperhand on overcoming your troubles.