As we said before he is tormenting himself, he misses his wife. "How you call to me, call to me", the echoing on those phrases give us a feeling that he is crying for help, in order to be together again, to join her. The author uses the technique of repeating the same phrase several times in order to make it more painful. Therefore we can see how lonely he feels.
We can say that he is completely alone because he refers to she as "the one who was all to me", the author is telling us that she was everything for him. It could be due to Hardy's treatment towards his wife during the last months of their marriage. Maybe he regrets of something or his behavior towards her. He is filled with guilt inside him, now he implores Emma to appear to him. The author even takes a risks as describes the exactly way in which he would like so her "Let me view you then, standing as when I drew near to the town".
As a conclusion of the first verse we can say that the author is trying to express how his wife changed. He hears her saying that she has changed from who she was before, "you are not as you were ", "when you had changed" the second quote is even more clear because he specific uses the word itself.