Period Pain

Taylah Hope • Born: 1997
I've been getting my period for a very long time now, and each cycle the pain gets worse and worse and worse. I have cramps to the point I can't stand up, and I (a nearly 19 yo) am reduced to the floor bawling my eyes out. Nothing helps that I know of. 
I've been to the doctor but we've found nothing to help with the pain, all she can do for me is prescribe me with codeine which makes me ultra sleepy and finally takes the excruciating pain away, but I have to take it every 4 hours to keep it away. 
Any tips or anything would be highly appreciated!?