Welcome to SR!! My DOC (drug of choice) was crack, though I did go through a period of abusing opiates I didn't have withdrawals.
There are many people here who have though, and I'm sure they will be along. I've read the withdrawals are like a bad case of the flu - keep immodium, ibuprofen and drinks like powerade/gatorade handy. Hot baths help with the restless legs.
Not saying you will HAVE any of these issues, just passing on what I've read on other threads.
Hugs and prayers,
Amy