As far as withdrawals, stay hydrated, immodium for the runs. You do need something for pain. Can you talk to your doctor? There's a lot of really good arthritis meds out there for long term use that aren't narcotics.
Withdrawals usually last (the worst) from 3 - 7 days - correct me if I'm wrong anyone. If at ANY time you don't feel safe, go to the ER. Please.