In Du Fu's "Ascending the Mountain", which sentence is the expression of the feelings of worrying about the country and hurting the country? Please make a brief analysis of this sentence.

"I have come three thousand miles away. Sad now with autumn, and with my hundred years of woe, I climb this height alone" further clarifies the feelings contained in the above two couplets, and shows the poet's melancholy when he was worried about his country and hurt his country in terms of time and space: one is sad and wandering, leaving his hometown in Wan Li; Two sad late autumn bleak, desolate and magnificent; Three sorrows Life is short and moody; Four sorrows travel to other places, visiting other places; Five sorrows climb the mountain in the old age, and they are unable to do so; Six sorrows are weak and sick, and the situation is difficult; Seven Sorrow Lonely, Sorrow Hard to Send ... The neat and rigorous antithesis is not only full of the poet's endless travel worries like fallen leaves, but also full of the poet's endless loneliness and hatred like a river, which makes us deeply feel the pulse of Du Fu's heavy beating feelings and the strong voice of the times!