When you suffer from depression or just have a miserable life that feels like a very cruel and direct rejection from others. I'd suggest to complement that with

When you suffer from depression or just have a miserable life that feels like a very cruel and direct rejection from others. I'd suggest to complement that with "can you make the person life better or make the person happier?" I can tell from your comments in this thread that you are exactly the opposite of a mean/cruel person, so this is a good example of what you said yourself: that even trying to be nice with others you might still come across like all the opposite. Of course your point is still equally or more important, as it becomes harder to help others when you can't even make a good life for yourself. But giving can be many times life changing for others.