how to help with insanely bad cramps

wver since my first period 5 years ago I've had debilitating cramps during my period. at best, they make me lightheaded and shaky when I walk. at worst, I haven't been able to walk at all and have blacked out entirely. that seems like cause for seeing a doctor, but I'm a minor and my mom doesn't believe me about the severity of my cramps (I've blacked out in front of her, by the way) and doesn't believe in using birth control as a treatment for things other than avoiding pregnancy. long story short, all I've got is advil and hot water bottles, but I'm desperately in need of something to make this better. any advice would be super helpful!!