how to get bc?

alright ladies, i’m 16 with the worst possible cramps in the world (horror movie knife dragged across my uterus slowly) and i bleed like a massacre. i get so nauseous that i sit in the school bathroom on the cold tile trying to get it to go away. i also have some bad acne spots that no matter how much make up, they just won’t be covered. i can’t ask my parents if i can get on it because i have a bf and they’ll think it’s because of him and definitely won’t let me get it. so how do i get it without them knowing? and also what is it like for the first month of having it because i’ve heard it can kinda be a pain in the butt for the first month or so. thanks y’all!!💞 oh and which pill works the best because i’ve heard of horror stories with multiple of them.