I would sympathize with people around me to work together and improve the situation.

I don't think this would be like in Hollywood movies, us against the others, but rather a community work. That being said, when I went to a big city the first time I felt exactly in this situation and resolved that by asking to a neighbor some help. And during holidays of the end of the year I had once my bank doing server maintenance, so I had to eat less and eat almost sweet potatoes everyday (quite cheap) for a couple of days. At this time I spent the new year eve in a Church with people from Philippines where the food was free and I went after to an African bar (free entrance) and someone I knew offered me a drink.