I'm not too sure, but have you ever thought you might have endometriosis? All I know is that it's a condition that gives you extremely heavy, painful periods.
I get hell periods as well, fainting, puking, but I've always been able to take medicine to help all that. It's different that you can get rid of the migraines yet you still have a heavy flow.
Like I said, I'm no doctor and not sure, and other
kr members know a lot about this stuff, but it might be something to look into.
Also, it's really important to be truthful with your doctor.