why was Johnny's dying so difficult for Dally to handle? why do you think Dally would have wanted to die?

Consider Dally's earlier pleading that Johnny not go to jail. He explains "in a pleading, high voice" that he just doesn't want Johnny to get hardened in jail. Ponyboy realizes how tenderly Dally feels for Johnny, and thinks about what Dally might have been like before he was toughened on the streets and in jail. Johnny was the only person worth loving for Dally. Both boys were basically orphans and Dally felt Johnny was his ward.

because johnny was the only thing dally had the only thing dally loved.. johnny was his everything and when dally lost it he felt he had nothing else to love for so he went and got shot

johnny was the closet thing dally had.