When I was in the Navy as a poor enlisted E-4, on more than one occasion I had to go to a food bank. I qualified for food stamps, too, but never applied for them. Food banks often provide food for people who are struggling financially but do not qualify for food stamps.
To do what? Were you feeding a family? When I was in the Navy, three squares a day were always served up on the messdecks.
And while I really don't want to get into the specifics of your particular situation, but if you were trying to feed a family, what made you think you could do that on E-4 pay?