(TMI) AF Question

Alright, so this may sound like a super stupid question, but in the 12 years I've had my period it's been normal for me.. So I honestly don't know.

I have extremely irregular periods (caused by pcos and hormone imbalances).

Anyway, my question is, how long is too long to be heavily bleeding on your period?

I go through about one Tampax Ultra tampon every 2-4 hours (and it's normally to the point that it's bleeding through, because that's when I notice it), about every year I have at least one period that lasts upwards of a month (I'm currently on day 22 of my period). I've had two different Gynecologists tell me that it's "just pcos" or "just menorrhagia".. But it makes my day to day life a pain in the butt for obvious reasons, and I'm sick and tired of it.

My cramps have been so bad before that I pass out from the pain, I'm also anemic due to it..