Prosperity,
No, I don't think you are being heartless and this person may very well be happy. Some people get a lot of attention by being sick. Sounds as if this person may be one of those since it seems that they are so willing to share their symptoms and treatments.
How to respond? Depends on how fed up you are. :-) Much more tactfully than I would in any case I'm sure.
Walk in beauty,
Rebecca
