The three-time champions confirmed on Friday that the 25-year-old will miss this summer's tournament due to a thigh problem.
Bender now admits that he is in a state of shock after being forced to withdraw from the squad.
"It's a dream that has been broken," he told Bild. "I need to process it first. I have to go for a rest. I've only just left the national team. I cannot tell you how I'll deal with it. I need a couple of days of rest and distance.
"I've been preparing myself and looking forward to it forever."
Germany have been drawn against Portugal, Ghana and the USA at this summer's World Cup in Brazil.