Wow. Your story sounds like mine.
At 13, I had my first period. Light, and only 5 days, with no cramps. I had a period free summer. But when I turned 14, that all changed. I had a "regular" period every month. It was very heavy and it would last for 7 days, 4 heavy days and 3 "lighter" days. By 15, the cramps started to get worse and I started to have two "regular" periods a month (they were exactlly 2 weeks apart, same blood flow, same duration, and same cramps). I went to the doc's and had an ultrasound done because I was "too small for a pap". They couldn't find anything wrong, so they suggested birth control pills to regulate them. I decided to tough it out, but by the time I turned 17, the cramps were unbearable, and I went on birth control for a year. This gave me 4 day periods, heavy-ish on the first day, and mild cramping. I stopped taking the bc almost exactly a year later, but the effects lasted untill the beginning of this year. I realized this because for the three months before I went "normal", there was no pain, they lasted 3 days, and they were light. The month I reverted back to my pre-bc days, my hubby thought I was having a miscarrage; I was in so much pain and there was so much blood, I litterally stayed on the toilet the whole day. When I calmed down, I went to the er, where the doc told me that I was just regulating and that my body was probably *finally* getting rid of the build up from the previous 3 months before. I have since returned to cramps that are so bad, that I have to stay home from work. (i start on the first wed. Of the month and the third wed.) they are now only 5 days long, but the first day is the worst. It is heavy and painful the first day. But for the remaining 4 days, the pain lessens to were I can function without having to down a bottle of pain reliever.... And the bleeding lessens considerably, where on the last 2 days, it is just a light discharge with no discomfort.
I have tried everything from heating pads to dangerous amounts of pain killers (only ib though). I resorted to trying to sleep the whole day to escape the pain, when my grandma called me up saying that she used to suffer this type of period too and suggested something called magnesia phosphoric (magnisium phosphate) pellets that are made specifically for menstrual cramps. For about $7.00 at any health store, you can get a "vial" of about 200-300 pellets (they are very small). You just let them dissolve under your tongue and almost instantly the pain dissipates. They are safe enough to take throughout the day in doses of 3-6 pellets every 4-6 hours. For me (6 foot, 175 lbs) I take 5 in the morning. That gives me enough reliefe to last through work (8 hrs.)
i know its a long post, but I hope this helps you.