How To Treat Painful Waistline?

Hi, I m 39 and I ve been experiencing pain on my right side waistline when i stand up from a sitting or sleeping position. It s so painful that i can barely walk for a few seconds. I thought at first that i must have slept wrong and it would go away. It s been over a month and it s not going away and seems to be getting worse. The pain seems to be inside not on the surface. Help!