Try doing some informational interviews of actual software developers in person. This is the single best way to get some concept of what the job entails short of actually just getting hired to do it. Also, keep in mind that every job is different. Maybe Ruby on Rails in a small shop is a disaster for you, but Python at a corporation is an excellent fit.

I don't think the modern world does a very good job of helping people figure out how to find a good fit. Some people luck into it. Others just miserably muddle through. Others just fail entirely.