The best way is really to get on the pill. Even if its not for prevention of pregnancy, it regulates your hormones on the pill. The other thing I suggest is alot of vitamin c and water, oh and zink too. You need vitamins to help. Maybe the multi vitamin with iron, zinc and vitamin c will help. My co-worker takes all of the above and it helps her very much. She told me she had some painful periods too. But all of these help. Good luck.
If you do not want to go on the pill you can try the depo shot. It is only four times a year. But, if you react badly you are stuck with it for the next three months. Have you been tested for endometriosis? You may want to consider it. You can have it surgically removed, although it will most likely come back. Or you can get pain killers. But, truthfully, they treat endometriosis patients with birth control also, so it may not matter. Just a thought.