Think about it. His entire Universe was destroyed, then he saw his entire Multiverse destroyed and was forced to live with the Golden Age Superman trapped inside a dimension and forced to watch the new Multiverse.
People say Batman is though because he can handle his parents death, and Batman is my favorite character.
But having your entire Universe destroyed and witnessing the events of every single Universe being destroyed > Your parents dying (on a worseness scale).
You have to admit, it's true.