I have the worst periods!

I hate periods so much! I started my period when I was 12 and never had any problems until I turned 14. That's when I started having long, heavy periods. I remember suddenly having periods for 2-3 months straight, having to regularly go to the doctor to have my iron levels tested, being on nasty iron pills, and having blood transfusions. I went off the pill when I was 16. That's when it happened the first time. I felt the urge to go #2 so I went to the bathroom. While I was sitting there on the toilet, pushing I started breaking out in a sweat. The urge to push #2 was so strong and the cramps were so painfully sharp, I passed out. When I regained consciousness I was lying on the bathroom floor, my entire body drenched in a cold sweat. I had the urge to puke and I did, several times. Once I had thrown up the pain seemed to lessen until I felt so cold and weak that I crawled pathetically down the hall to my bedroom, got into bed, and went to sleep. Ever since that time, my first day of my period is like that every month. If I do not take two Ibuprofen before my period starts or if I wait until the cramps are already here to take the Ibuprofen, I will go through the sweating, passing out, and throwing up. Ever since age 16 I've been to endless doctors, ER's, had many tests done, but nobody can give me an answer. I'm 31 now. I feel I should mention that I don't think I'm just some wimp with low pain tolerance. I gave birth naturally(no pain meds) and survived. So why does my period make life so miserable?