Weaning off opiates can be difficult especially if you are using them to treat real pain. The first question is if you are still suffering from back pain. If so, you must first treat the underlying cause.
For example, if you suffer from bulging discs or spinal stenosis, epidural steroid injections is an alternative to taking opiates.
Once your pain symptoms are properly addressed, you can then start to taper the opiates. You must work together with your doctor. He/she will likely switch you to less potent narcotics like vicodin and tyco#3 first before you are completely opiate -ree. This process can take months, but with your doctor's help you can be successful. I have many patients like you who became dependent on opiates, who are now opiate-free.
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If you do it slowly( in your case 3 months is a good time frame), and if you have the help of your physician and some less potent opiates like vicodin as a back up, you should not suffer too much.
In my experience, people who try to wean themselves without their doctors' help are rarely successful. If you don't like your current doctor, find somebody else. You want to be able to call someone when you need advice. And again, your doctor can give you some tyco#3 and vicodin so you don't go back to the oxycodones when you have symptoms of withdrawal.