But how well you do your job should not be seen as the measure of your worth.
God has claimed you and has called you one of his precious children. That identity and that claim on you is what defines who you are and your status in life. In truth, the reason you are to do well in school is so that you might do well in the world. You learn so that you might be a servant. The information you absorb and the ability to solve problems prepares you for the opportunities you will have to help the world look more as God would have it be.
Study hard; do well. But when you find yourself becoming too overwhelmed remember the simple phrase used by Martin Luther whenever he was in distress. He simply spoke - out loud, even if to no one other than himself - "I am baptized."