A woman who retired early at 58 thought she was ready with over $500,000 in savings. A few years later, it was gone.

Misty Miller retired early in 2016. She now works full-time.

Austin Meyer/Business Insider

• Misty Miller retired early without a plan.
• When she tried to get her job back, she couldn't.
• On a whim, she cashed out her entire 401(k) and regrets it.

Misty Miller thought she was ready to retire.

She'd paid off her mortgage, minimized her monthly expenses to $800, and had over $500,000 saved for retirement.

"I did the math. If I retired, my pension check would net me $3,000 per month...