In trouble with principal because of assignment "handed in late", please help - need advice...?

Calm down. Your parents don't hate you. They are strict with you because they know how important it is to do well in school. I hope you saved all of your assignments. Take your assignments out of your notebook and show everyone that you did, indeed, do the work. I suggest you talk with your counselor. He will probably be more sympathetic than you suppose. Do not try to accuse your teacher of being a "s*itty" teacher. The teacher will feel he has to defend himself and this will only make matters worse. Just say that you are trying your best and been doing much better this year about getting your work in on time.