What Causes Painful Menstrual Period?

For the past 4 months, the first day of my mentrual period is extremely painful. Each month, the pain is getting worse. I have always had generally painful cramping but lately it is cripling. I was laying on the floor yesterday in extreme pain and it led to throwing up and horrible sweats and my face being white as a ghost. Im really scared. Any suggestions of what might be causing this?