When Holden is drunk in the park why does he begin to think of what would happen if he were to die?

Holden is in the park, in winter, at night. He is cold already, but then he thinks of the duck and how if they were there they must be cold, too. Holden begins looking for the ducks by the water and he almost falls in multiple times. He gets a bit wet and is now freezing. He sits down on a bench and thinks of how he may get pneumonia. He's worried about that,but stays on the bench and thinks of his family. Holden questions how they would react to his death. He knows D.B. and his father will grieve, that his mother is still not over Allie's death, and that his sister would probably never get to go to his funeral because she's a kid. Then Holden gets angry because if he dies all his phony relatives will come to his funeral, like with Allie, and pretend to grieve his loss without ever really knowing him. He takes out his money and counts it, then he goes home to see Phoebe.