Well my dad's girlfriend is a doctor, and she has quite the story. She had a child when she was 16, and had to begin working to support it. She became a lab tech for awhile, but she had always wanted to be a doctor. So when she was I think 31 or 32 she went back to school. She's very smart and achieved near hundreds in university, so they accepted her into med school after one year.

This story can maybe show you that it is possible to go back at your age and become what you want to become.