I had a conversation with a friend tonight, about the way you feel when the sky stretches out so endless above you that you might just drown among the stars that you will never, ever reach, and how insignificant that makes you feel.
Apparently that feeling of insignificance triggers different responses in the two of us. For me there's a sort of desperate longing, but also a comfort. Like it's all going to be okay, because in the end, I'm only a tiny tiny part of a much greater whole that I can never hope to understand, and I have faith that there is a Pattern there. For my friend it is sheer despair, a sort of what's-the-point-of-anything*.
I wish I could make that better for them. But one of the unfortunate parts of growing up is realizing that you can't actually save anyone from their own demons- there is no way to love someone healthy, no such thing as a white knight who can rescue someone from Depression. Only the afflicted can fight their battles, and the most anyone else can do is stand by them, offering support and encouragement and ass-kicking as needed.
And then try not to blame themselves if the war is lost.
*(Of course, that's not to say I haven't also had that reaction at various points in my life. But by and large, I think I come down on the, "It's going to be okay," side.)