Being thrust into an unfamiliar situation can be rough. You have no idea what you need to know or are expected to know, and sometimes you’re pretty sure your current skills aren’t enough.
Relax! The first step in making yourself believe you belong there is acting like you have every right to be there. A little projected confidence goes a long way toward making everyone (including you) that you belong there. You can be a complete mess on the inside, but no one will ever guess that as long as you act with confidence.
The second step is to keep up the act. It sounds crazy, but maintaining the act requires you to learn and practice the skills you’re pretending to have. Before you know it, you’re no longer acting. You’re doing.
You can even move yourself into that dream job by pretending you already have it and doing what others in that role already do. You pick up the skills and attitudes you’ll need.
With a little confidence and a lot of learning, you can turn things around and make a more successful situation for yourself.