J.C.
Well, first of all don't feel embarrassed, most women go through this at one stage in their life or another, even if they won't admit it. I went through a depression almost exactly at the same stage of raising children that you are.
One of the best books that helped me through it was "Learned Optimism - How to Change Your Mind & Your Life" by Martin E.P. Seligman, Ph.d. Learning how to recognize and interrupt my negative thought patterns helped me get back on the right track, plus I learned about how the brain chemically functions and what is going on. Another book that helped me laugh through the trials of motherhood and gave me some good coping advice is "What No One Tells the Mom" by Marg Stark. I also started walking, getting proper nutrition, and doing yoga when I could squeeze it in. It's hard to force yourself to do all this for yourself when busy with little ones and depressed but make baby steps and it will get better.
I don't have much time in my busy day but if I can even squeeze in my 20 min PM yoga video before I go to bed, it at least helps me feel centered and that I've done something for myself. I have a hard time eating right, but I take URIlife whole food juice powder that tastes good and only takes a few seconds to add water and drink. Their supercharged version gives me an energy boost when I'm feeling run down (with natural caffeine from green tea and other herbs). Contact me privately and I can send you a free sample. www.urilife.com/NutritionForLife/products.html
The biggest thing is to ask for help and take time out for yourself. It also helps to have someone to talk to (which it sounds like you've found through a psychiatrist). Don't be afraid to talk to other moms or your friends to get their support and ideas that help.
You're not alone! Don't hesitate to contact me or reach out to others you feel safe talking to.
A little about me:
Work-from-home Mom of very active 3 yr and 5 yr old boys & part-time after-school care provider at my kids' Montessori school.