Cramps are stopping my day to day activities.

I get the most painful cramps ever, sometimes to the point where I'm doubled over in pain and on the verge of being sick! I'm 16 and have had my period for 4 years. I've been to the doctors and have been prescribed lots of different medication but nothing has quite helped for the cramps. Is their anyone who has shared the same experience as me and has found a way to minimise cramping? Please help!