How should i tell my mom?

heres the thing, im 17 almost in the middle of my junior year in high school. my parents are divorced and since….the 6th grade..my dad wanted me to move in with him like 40 minutes away because he thinks ill do better in school. (btw i suck at school..im failing two classes and well yeah.) my dad is married to a school teacher and lives in a good part of NJ with a good school. now just recently i gave in to my dads attempt to go over there. now the thing is how do i tell my over dramatic mom?.

my mom is known for being this crazyyy person who yells and scream and such…and not only do i crack under pressure but i also am very shy and timid…and hate confrontation. please help