after the birth of my child i jumped on the injection for a month and then had an iud put in

Omg i thought i was the only one going through this its a relief to know im not :-) im 30 ive just had my 4th child  6months ago and before that i had regular monthly periods after the birth of my child i jumped on the injection for a month and then had an iud put in a month later since then my period hasnt stopped ive been bleeding for 4 months now with a day or two off every month accompanied with lower left pelvic pains that shoots through to my legs now and then just a few days ago i started vomitting :-(