Opiate withdrawal isn't pleasant. Codeine is far from the hardest opiate to kick but it will be unpleasant - really peeking your misery in about 12-24 hours after your last dosage. This is't medical advice. This is what I did while in opiate withdrawal which is rarely dangerous or fatal. Bundle up, get movies, sip chicken broth, take hot baths and showers, sip ginger ale and juice to hydrate or popsicels, use tiger balm and heating pads for sore and achy muscles. Stay away from caffiene. Go on gentle walks to detox. Just make yourself comfortable as possible and you won't want to be social at all. You'll feel like you have the flu for a bit.
And then as soon as possible or tonight if withdrawals aren't intolerable yet (and they might not be!) get to an AA or NA meeting. Just sit and listen and ask for the book and maybe a phone number or two. Just walk up and say, Want to exchange phone numbers? People want to. It's not weird at all. And they are of great use to you right now - because they have been where you are.
Getting sober is fairly simple but staying sober so you never have this fear and dependence again will take some work that you will be able to do by just gently pushing yourself in the right direction.
Pray.
Stay here and keep posting!!