12th day clean of Opiates

I'm on 12th day of being clean of opiates and its tough. The withdraw symptoms came back full force.
I'm sweating like crazy, but have ice going through my veins and goosebumps like crazy. Diahrea like crazy and anxiety through the roof.
Tonight i decided to go to a N/A meeting for the first time ever. This was the best thing I could have ever done. It made me not feel alone. I got a sponsor who is a few years older than me, but struggling with the same thing. We have the same story and he has been clean for a long time.
My question is has anyone done NA and what was the outcome? I have always been ashamed of my addiction, but now I learned its a desease and its as shameful as having cancer.
Anyone with NA experience please help me with what you learned, what helps, how long to go?