What is the name of this story?

What I can remember is that it was a short story approximately eight pages in length. (Keep in mind, there may be a bit of deviation from the actual story) The major collections that I've read over the past few years have been by Arthur C. Clarke, Robert Silverberg, and Ray Bradbury (not that the many others aren't amazing! I just haven't progressed too far...). Anyway, the story was about a mysterious man who would somehow remove people's worries and doubts. The opening scene, if I remember correctly, was a dinner party, in which the man moved from person to person, leaving each guest feeling elated afterwards. Upon leaving, the man would become depressed, feeling all of the depression that he had absorbed. In the final scene, a young boy sits on a park bench with the man, and tells him his worry. I believe the man explodes, disappears, etc., due to the weight of the boy's worry. It was beautifully written, and it's been bugging me for a while that I can't remember the title...