Vital Records: How Do I Get Something Off My Medical Records

I am in the state of North Carolina and I have deteriorating disks in my back and I have had 2 surgeries on it already and need a 3rd surgery but there is a chance I will no longer be able to walk again if I decide to get the 3rd one,so my other option is to see a pain management clinic. I had an appointment today and they said they couldn't prescribe me pain meds because I told the hospital a while back that I smoked pot back when I was a teenager ( 20 years ago) so because they put that in my medical records I cannot get the proper treatment I need! How do I go about getting that removed so I can continue treatment?

Vital Records: How Do I Get Something Off My Medical Records