They were self-sufficient in the sense that there was no one coming to help in case of emergency. That doesn't mean they ever felt secure. Entire families regularly died for one or more of dozens of causes: starvation, freezing weather, tornadoes, human sickness, livestock sickness, crop failure, drought, dangerous animals, Indian attack, crime, etc. Some of them might have pretended at a "control over their lives", but few modern Americans would trade places with them.