Human beings make me anxious. And the damn things are everywhere.
Social interaction almost always makes me feel disappointed later on when I analyze how it went. Said analysis usually leads to frustration and depression, too.
Content, happy people make me depressed.
Animal abuse makes me very, very angry.
And beautiful things make me especially lonely when I remember how I have no one to share them with. I don't mean cars and jewelry, I mean things like sunsets, falling snow, songbirds, walking on a deserted beach by moonlight, etc.