For sure that feeling passes, you just have to give it some time, every one recovers at a different rate, but ... you WILL recover and feel normal again...typically, it takes between a week and a month, and since you're habit was only to codeine, and not *that* much of it, I'm betting for you it'll be closer to the shorter end of the spectrum.
I also recommend MEETINGS!!! AA/NA, either one (sounds like they both fit for you anyways) or both ... is a great idea! Keep up the good work, you can do it
Think of how fast a couple or three weeks usually goes by, that's really all you have to tough out here, and then ... FREEDOM!!!
It's so worth it, butterfly, and you are worth it. Keep posting, and let us know how you're doing. We've (almost) all been there, done that, and would love to be of service.