Why did the narrator in'A Doctor's Journal' feel hopeless?

The poem “A Doctor’s Journal Entry for August 6, 1945” is a horrific description of the bombing in Hiroshima. This poem depicts a shift in the mood as it starts with a calm, beautiful and warm morning scene and goes forward to describe the tragic incidents that took place that day. This is an anti-war poem written in the form of journal entries. One will definitely be horrified by knowing the devastating effect of war on the inhabitants of that place. The poet sympathizes with the victims of war thereby reflecting humanity. Through the poem he is speaking with his wife, giving her hope and assurance that the situation will turn out to be better. The poem is a record of the incidents in the form of a narration which describes the situation of the author and how hopeless he felt at times.