One of my biggest personal failures is my inability to convince those around me to stop sticking with jobs/careers/industries/etc they hate.
If it doesn’t feel right, don’t settle on the first or second career field you dabble in. Keep searching. Eventually you will find work you love to do. If you catch yourself working hard and loving every minute of it, don’t stop. You’re on to something big. Because hard work isn’t hard when you concentrate on your passions.
It doesn’t matter what you have already invested. You will never get that back. Look forward and find something you love to do (and yes, it is possible for everyone).