Why is it that Eliezer "could have screamed in anger"?

Eliezer said, "I could have screamed in anger. To have lived and endured so much; was I going to let my father die now? Now that we would be able to take a good hot shower and lie down?" 

I believe this quote speaks for itself. Eliezer and his father had supported and held each other up through everything...... and because they were together...... they survived. To lose his father at the very end of their ordeal, to know that his father had endured beyond his endurance only to die before seeing the end would have been devastating. In this quote we can feel his frustration...... his anger.