I'm so with you here. At my baseline, I'm slightly more introverted than extraverted, but manic, oh man, total 180. Bring on the people. Depression, though, makes me a total hermit. Like Emily Dickinson level hermit, and then when I finally come out of my shell and feel normal and/or hypomanic again, I fantasize about running off to some city where no one knows me and changing my name. Not exactly something that would help the loneliness ... Just fuels the cycle.