Obviously your body is bleeding more than it's designed to bleed. It's gone wrong or you would not have health problems from it. The main way to develop anemia is blood loss. Birth control pills stop blood loss. That means there is a reason for taking them. There are plenty of reasons not to and anything you take can cause death but everyone that does take them has a reason. There are also several things that can go wrong and cause heavy bleeding which would require major surgery if people didn't take birth control pills. Many of those same things can require removing your uterus or ovaries which means no chance of children if you don't slow them down with birth control pills.

Again talk to a doctor. Whether you are religious or not you have to admit we are not perfect. Things go wrong with our bodies. It just depends whether you believe in finding out and treating those things or suffering with them and potentially dying from them. Along with what treatments you believe in.