He was uncomfortable. Treatment had not gone well. There was more pain as the disease progressed. There were times in the past year when things seem to be getting better, only to turn badly again and his condition worsened. Almost immediately I realized my response was unsatisfactory.
People get sick.
Not all of us react the same way to these conditions. For some the process of dying is frightening and lonely. For others it is embraced and tolerated. It is not a matter of personal strength. In time any of us can grow weary and sullen.