I can't stand my mom

Dear Reader,

My mom is a person I can't deal with right now. I have to live with the realization that I will forever be the biggest disappointment to my own mom. She keeps saying that she believes in me and that she thinks I can do great but then she keeps accusing me of not doing my work in school so it is practically impossible for me to prove myself to my own mom. I would feel bad for my mom because she has to put up with me even when I'm not the best of all daughters but she threatened to burn my favorite things if I fail in school. If she burns my things, I won't have a phone, tablet, laptop, PS3, TV, or a diary. I know a lot of this stuff is materialistic but how would you like it if your parents barged into your room and began burning your property. I have a feeling you wouldn't like it either. My mom only said this because she's mad about the fact that I'm struggling in chemistry but I'm trying to improve my grades and knowledge in that class so she shouldn't be brash with her words. What do you guys think? Am I wrong or my mother too extreme?