Server pain while on period

Hello everyone. I have a few questions and concerns about my periods. To give you a quick review prior to the problems I have been having. I got a tubal Ligation done in 2000 and since then nothing has been the same. Prior to the TL I NEVER had a cramp. I was 28 yrs old when TL was done. Since the TL my periods have been so wacked. I don't know when they are coming. Sometimes I get two periods a month lasting 8 to 10 days. The pain has gotton worse over the years to the point I can hardly function anymore. And the pain is always there rather or not I am on my periods. Now it is server when I am on my period. The pain is only on my right side. When I start my period my right hip will hurt to where I actually walk with a limp. And the pain will last the whole period. I have heavy bleeding to were I have to wear a tampoon and a heavy pad just so I don't soak through. And change it every hour to hour in a half. The pain includings not being able to move without the pain. My right hip, right pelvic area hurts, right leg will hurt. I have a very high pain tolerence (sp) for I have had three children natural birth no pain killers. And this pain is worse. Now when I am not on my periods I have a consent pressure on my right side. It does hurt to sit and the pain in on right side. Hurts to lay down on right side. I did go see my gyn and she found a polyp in my uterus in to which we are removing. But I am wondering what is causing all the pain I have. And would a hys. be the best option for me.