One of the beauties of poetry is that it can be interpreted in different ways by different readers, as each person brings his/her personal perceptions and experiences to the reading process.
In my reading of The November Guest, I don't hear the speaker saying that he is unable to react due to the sorrow he has experienced. The speaker recognizes that his surroundings are what many people would interpret as being bleak, depressing and sorrowful in nature. The trees are barren, the ground is wet and sloppy, there are no colorful birds - actually, the only color mentioned in the poem is grey.
However, the speaker sees beauty in these images. He states that he has "learned to know the love of bare November days" and, in spite of the presence of sorrow, he appreciates beauty in the mist that has fallen on the grey surroundings and changed their color to silver.