toddler attitude is HORRIFIC

my two year old son, gives me the hardest time when he is grumpy, he will literally smack me, if i tell him NO he throws himself on the ground, he smacks my dad, he smacks everyone 😭😭😭 he is so mean, he tells me no all the time, i just don’t know what to do, i feel like he’s the parent LOL 😭😭 his attitude has gotten so bad and i literally don’t know what to do, i’ve tried trying to distract him with toys and etc im just so frustrated myself. how can a person this small have an attitude like a grown man. please help