Finding job that not only pays the bills, but also gives us meaning and purpose is a relatively new idea.
For example, during the Industrial Revolution, work was a means to a goal, a way to make ends meet.
Despite the changes of today, profession decision confusion is normal. Some career-seekers have nearly unlimited alternatives. Psychologists call this choice paralysis.
Confusion is natural, and worry is a big part of finding meaningful job (it's hazardous), but it can be overcome.
Everyone is good at something. Our talents may not be as obvious as others'. Instead of math, we may be strong at kids or gardening.
Many people won't see your natural strengths. We shouldn't expect a supernatural calling on what to do with our lives, thus we should be pragmatic in finding a fulfilling work.
We should be kind to ourselves if we haven't found rewarding work yet because it's hard (for many reasons).