OxyContin is a slow release pain medication. To avoid feeling sick with withdrawal symptoms it should be gradually reduced. DO NOT BREAK, CHEW the pill, too much OxyContin will be released into your system. Ask your doctor to gradually reduce strength of OxyContin.
I weaned myself off of Librium a few years ago by lengthing the time between pills until I was 6-weeks between pills. This eliminated withdrawal symptoms. I had failed before even tho I was only on 5 mg. Took me a long time do wean off of it, doctors insisted I was not addicted, but, I was.
A reduced strength OxyContin over a period of time, keep reducing strength, will probably work for you.
I am not a medical professional, speak only from my personal experience.
Cold turkey stopping can cause serious withdrawal symptoms, misery I could not live thru each time I tried to stop cold turkey.