I hope my reply will help. You don't need to internalize every ignorant comment you hear in life. People form their opinions from a lot of raw materials, and not all of those materials are good input to making a reasonable opinion. This person who upset you was being metaphysical when what you probably needed was just a calm listening ear.

There is nothing wrong with needing to digest what other people say before forming your own reply; if you need to say anything, you can always say "Oh, I'd have to think about that" or something else that acknowledges the person said something without giving your set in stone response or opinion of it right then.

I see no stigma in mental illness and by that I mean I refuse to acknowledge it. Mental illness is no different from a broken leg or sinus infection--illness is illness and people recover in varying degrees over varying lengths of time. I never let anyone make me feel bad about my depression; to do so would only add to my depression and it's a big enough monkey on my back as it is.

Still, if it does bother you, you might read up on prejudice in general. All of that said, though, I don't tell many people about my illness, because I recognize some people can't handle their discomfort with it. I hope you feel better soon.