All credits are enough to get a diploma.
But that doesn't mean it's over if you don't pass the exam. If you don't pass the exam, the school will organize a make-up exam when the school starts.
Just pass the make-up exam. If you fail the make-up exam, you must continue to take the next make-up exam. . . In short, don't think you can hide in the past, this one can't escape.
However, make-up exams are usually very simple. You can read and study casually during the winter vacation. Mathematics is very useful and will be used in your professional investment and financial management. Study hard.