How long can withdrawal syptoms from percocet last?

I sustained an injury to my back earlier this month. For the last four weeks I have been taking 30 mg of percocet daily. I became tired of the side effects and did not renew my perscription. I became extremely sick about eight hours after my last dose. It has been 48 hours since then and I can barely move from pain / naseau / depression which I believe are symptoms of withdrawal. When will I begin to feel better? Any info will be greatly aprreciated.