What does Candy realize that makes him particularly angry towards Curley's wife?

In the next-to-last chapter of the novel, both Candy and George agree that Curley will want Lennie lynched for killing his wife, and that the other men will go along with Curley. 

Now Candy spoke his greatest fear. "You an' me can get that little place, can't we, George?" You an' me can go there an' live nice, can't we, George? Can't we?"

Before George answered, Candy dropped his head and looked down at the...

In the next-to-last chapter of the novel, both Candy and George agree that Curley will want Lennie lynched for killing his wife, and that the other men will go along with Curley. 

Now Candy spoke his greatest fear. "You an' me can get that little place, can't we, George?" You an' me can go there an' live nice, can't we, George? Can't we?"

Before George answered, Candy dropped his head and looked down at the hay. He knew.

Candy realizes that without Lennie, George would have no interest in buying the little farm. It was a shared dream, and without Lennie the dream is dead. George and Lennie could have shared all the hard work. Candy would be nothing but a liability. George would have to do all the hard work by himself, as Candy is already an old man and has an injury. Even if he had the use of both his hands, he couldn't take Lennie's place because of his age and the fact that he and George have never been friends and never could be friends like George and Lennie.

When Candy realizes the dream is dead, he becomes angry at Curley's dead wife. After George leaves him alone with her, he takes his anger out on her, saying,

You done it, di'n't you? I s'pose you're glad. Ever'body knowed you'd mess things up. You wasn't no good. You ain't no good now, you lousy tart.

The old man's wrath is understandable, even though the lonely girl is hardly to blame for her own death. Candy is devastated because he will never have such an opportunity to attain independence and security again. 

His eyes blinded with tears and he turned and went weakly out of the barn, and he rubbed his bristly whiskers with his wrist stump.