In the S. E. Hinton novel, The Outsiders, Darry has several reasons to be angry. Never mind the grief he must suffer over the death of his parents, but now he finds himself a father to two younger brothers who need a father figure, but might not want to submit to his authority in that respect. He quit school in order to take two jobs for their financial survival. This is not financial security; it is financial survival. He’s stuck in a situation beyond his control, and he sees no signs of it getting any better in his near future. In addition, Ponyboy fights him over almost every rule he tries to establish, and this could result in the brothers being split up.
Enotes has some great resources.
Darry is a very hard working guys. He works in the morning and at night with two jobs. Making him stressed out.
darry is always mad because he has the responsibility over two kids lives, even though he's pretty much still a kid too. ponyboy doesnt always seem to recognize that he's under a ton of pressure and chose them over college. plus, he know if he does even one screw up, their whole lives could fall apart.