Food "stamps" are a safety-net component that has two purposes:
1. Help out families who need temporary assistance to provide food for their tables
2. "Pull" food through the supply chain so that farmers will continue to grow food, distributors will continue to move it to market, and stores will continue to sell it.
The US government is pledged, by law, to assist farming enterprises with price supports. That means that food products are not allowed to "float" on the market in free trade to find their price level--the price is kept artificially high so that the farm corporations will stay in business. Although you didn't ask for a lecture in economics, I hope it makes you feel better to know that one of the reasons your parents need help buying food is that food prices are kept artificially high.
I'm sure you do feel strange about your family's change in circumstances. One of the best ways to deal with temporary depression and concern about what others will think is to take charge of your own situation. There are things you can do to change your circumstances.
One of the things you can do to help out, even if you can't get a job right now, is to grow food for the family table. It truly does not take a huge amount of space--just dirt and sunshine and water. I have grown tomatoes and peppers in 5-gallon buckets on the back steps. I live where we can garden 12 months a year although I don't have much space for a garden. What I have is two patches next to the walkway that are about 2 feet wide and where I am growing turnips, mustard greens, onions, and broccoli right now. If you're going to start as soon as the weather will allow you, the first things to plant are lettuce, carrots, parsnips, and English peas. When the lettuce and peas are gone, plant something else behind them. You'll need to do some research to determine what, when, and how for your part of the world, so start with your County Extension Service agricultural agent (check the phone book). Here's a good reference to start you off: http://maryeaudet.hubpages.com/hub/What-To-Plant