11 day period!!!! HELP

Like half of girls say "oh mines only three ahaha" and I have 11-12 days of extremely heavy bleeding and PMS and cramps that make me curl on the floor and cry. I've been told to go on bc so I did and I've tried too many brands to count! And the doctor says there is nothing they can do about it. But it ruins my school life envoking stress and untamatly bringing my grades down. Seriously I need a life saver right now. Periods shouldn't be like this?  The pills actually didn't do jackshit to help anything