Suggest Treatment For Severe Pain And Bleeding During Periods

hello sir ,
i m 25 yr unmarried female and have sever pain during my periods. and feels like something is forcing my rectum from inside and that area hurts alot . i usually have peroids for 3-5 days. and use to change pad every 8 hrs. so i dont think the bleeding is excessive. please help me as i m nt able to go to work during period days..
thank you