I think when people are depressed they're extra sensitive to critisism. Well, I know even when I'm NOT depressed I take critisim very very badly and so I can really sympathise with you for having been personally critisised like this.
I don't know if this quote will help you, but it struck something in me, it's from a self help book, I think, and this bit is talking about not taking things personally --
"Even when a situation seems so personal, even if others insult you directly, it has nothing to do with you," writes Ruiz. "What they say, what they do, and the opinions they give are according to the agreements they have in their own minds.... Taking things personally makes you easy prey for these predators, the black magicians.... But if you do not take it personally, you are immune in the middle of hell".
It's true though, it's very hard to understand the nature of depression unless you've been there or known someone well who has. I suppose if they knew, they wouldn't be so quick to critisise in such harsh ways.
I think we partly do need to 'learn' to be less sensitive, sometimes, though. Well, me personally I know I could be much less sensitive to any form of critisism (even when it's not meant that way), I think it would benefit my life if I could learn to not take things so personally and get upset over people's remarks.
What don't you like about hearing other people's happy stories? Do you have a tendency to compare, and think that you are not as good as them, perhaps? I do tend to do that a bit, I've had to stop looking at my 'friends' profiles on facebook because I do get quite jealous, seems everyone is so happy and doing lots of things, it makes me feel bad about my own life... but I'm working on it and thinking what I could add to my life to make my own life more 'fun' (I do think people are having much less fun that facebook suggests, though!).
I hope you are doing ok, try not to be too upset over the nasty remarks, you have to wonder what is 'wrong' with that person that they so readily insult you, I mean, why would anyone feel the need to insult a stranger? Most people would be hurt by that, so the person insulting you might have their own issues and their own reason for wanting to upset others.