I have heard only anecdotes.

My own: I had a cat living out of my office. (I'd found him hit by a car months
before.) I was working late one night, trying to finish a lesson plan. I was
tired and somewhat depressed. My cat was contentedly sprawled on a desk a few
feet away. I was working at my computer at another desk. At some point, I looked
over at him with I think it's fair to say despondency in my eyes. He looked back
at me, got up, leaped down, then leaped on my lap. He put his paws on my chest
and nudged my face. He sat with me for several minutes. He'd never done anything
like this before.

A PhD scientist once told me, with a twinkle in her eye, that, "Cats have
mysterious powers... " She was kidding around, and yet, I think she and all of
us know there's something to this.

I hope you're well soon. I admire your cat. :-)

Our cat Raisen does a similar thing.  When me or my fianc? are feeling down,
especially painy (we've got chronic pain), or just feeling sick, she comes
to us from wherever she is in the house.  She sleeps with us every night at
the foot of the bed and when I have a nightmare, she will come up and lay on
my stomach until I settle down.

on 26 Dec 2003:

I only know anecdotal stories but I can add my own.  Even before my son
died, my cat Shadow was always in tune with my emotions.  If I cried, he
would be right there to headbutt me and make me feel better.  When I sing,
or if he heard something on the radio he likes he would actually sing, too.  
Since my son died I cry a lot and he always hears me even if he is in
another part of the house and he comes to comfort me.  He has never been a
lap cat but he'll head butt my leg and sort of meow at me and jump up next
to me.  

I don't know about healing powers, but I know for sure that a cat can sense
when you are not feeling well.  Every time I get sick (Cold, etc) and I am
in bed miserable, the cats always seem to give me a little extra love and
attention.

Here is a link to studies on the stress-reducing power of pets. It
sounds reasonable to assume that when you reduce stress, the body heals
more rapidly.

http://www.lifeclinic.com/healthnews/article_view.asp?story=509274

BarB