RIght after I had my RAI done I had excruciating cramping through my entire body. If I turned the wrong was stretched the wrong way even yawned funny. It was so bad that I cried and cried and cried. A little helpful advice, if you start cramping in your legs, walk…. The second you stop moving it tightens up more and gets worse. I found that if I pushed through it and didn’t let it completely tighten that it would go away faster. Once my levels were fixed the cramps stopped and my muscles strengthed up again. I feel your pain though and I hope that you will get through this quickly! Drink lots of water and if all else fails go see your specialist!