Are you just snorting it? Cold turkey. Are you smoking it? Cold turkey. Cocaine does not stay in a body for a very long period of time. If you are only doing the cocaine, then your withdrawal will be mostly mental; physical withdrawal may be 3 days with some tiredness after that, followed by learning to live without that stuff to rely on!
You can do this!
Therapy, AA or some program of recovery can help you!
If you can't quit on your own, seek a rehab place for at least 30 days. I have extensive personal research on this particular substance. This was my experience.