In my school, when you take a class over, the new grade takes the place of the old one. You might see if that is true for this class, do as well as you can the rest of the semester and then take it again (which you will probably do anyway if you withdraw?). Otherwise I would think about withdrawing and paying my parents back for the class (whatever amount was lost) if they paid for it or seeing if I could just change to pass/fail or auditing that class, etc. I would come up with a plan and explain to my parents that class did not work well for me this semester but that you are going to take it again at X time and/or take Y class instead, etc.