Not happy in my career

I don't feel fulfilled with my job. I have a bachelors degree in business and I'm not even using it. I work from home for a health care company. I like working from home but I feel like I need more. I want to go back to school but I don't know what I want to do and school is so expensive. I would love to do something in healthcare because jobs are always available. Has anyone been in this position or do you have advice for me?