Tell your mom you are starting to get sad and can't focus durning class cause a big rain cloud is always over your head she will under stand and then you will be able to do anything and she will bend over to help you in any way
"50 years ago we'd shove a fork up your fucking ...... ass!"
Or, just stop being a wimp and do better. If youre smart enough for the classes, you have no excuse for doing shitty (unless you arent trying, which means she is justified). If you arent smart enough for the classes, take lower level classes.