Iron level is 4 and reserve is 0 and constant bleeding?

i have been anaemic for a few years now but in the last few months has got alot worse. my doctor has give me iron supplements which have not worked in the past. i have got a problem with my menstrual bleeding and have been bleeding for 11months now without stopping yet my doctor or my gyno don't seem alarmed by this despite me having iron levels so low. how low do your levels have to be before you have to have a blood transfusion? im worried that my gp isn't taking this seriously. has anyone bled for this long and what was the problem. i do have pcos and that wat they are blaming this bleeding on but im not convinced and i thought pcos was suppose to make you have irregular bleeding not constant bleeding? any advice would be great