Only since the Industrial Revolution have most people worked in places away from their homes or been left to raise small children without the help of multiple adults, making for an unsupported life.
My own nature hovers between neurotic and paranoid. I've developed the habit of mentally listing things that make me optimistic about the future. I do it every day.
No one else can take risks for us, or face our losses on our behalf, or give us self-esteem. No one can spare us from life's slings and arrows, and when death comes, we meet it alone.