3 ideas
Instead of treating his anxiety as an illness to cure or a flaw to hide, the writer tells his lover that fear is his very substance and perhaps the best part of him. Seen this way, asking such a person to overcome their fear means asking them to stop existing. A lover can only accept the fear along with the person or reject both.
He describes himself as a forest animal that crept out of its dirty ditch, lay down in the clearing beside her, and was briefly happy in a warmth it had never known. Then the animal remembered what it was, could not bear to be seen in the light, and had to crawl back into the dark. The image explains how being loved can make someone who feels unworthy flee the very thing they longed for.
After months of letters, the two spent four unexpectedly easy and happy days together in Vienna, which seemed to prove that the correspondence could become a life. A later meeting at the border town of Gmünd went badly, with fear and misunderstanding. Soon afterward he asked that they stop writing and stop meeting, showing that a bond built mostly on letters can break when it has to survive in person.