The acute withdrawal period is going to be 72-96 hours. This will be the time when you are least-functional. Many people are essentially bed-ridden for this period of time. Your dosage of Codeine is nothing crazy. It is enough to cause a significant withdrawal. Either way, it should be manageable. Withdrawal is extremely subjective. There are people I know who have withdrawn from 100mg Methadone like it's a bad cold and I've talked to people for whom Kratom withdrawal makes them contemplate suicide. Generally, there is a middle ground in all of this that allows us to know that you're usage is in the more moderate category. Willpower and discipline should be enough to carry you through the acute part.
You will likely experience a more mild, yet still significant withdrawal for ~10 days following your last usage. This typically is experienced as increased anxiety, partial insomnia, perspiration and temperature-intolerance. The cravings become fierce after the acute withdrawal ends. When you're sick, the urge to use Opioids is like a person in the desert needing water. It's visceral and in your face. As your body goes back to normal, these cravings become a little more esoteric, like sex, maybe is for most people. Your imagination kicks in. Your ability to plan, scheme, not to mention use your body effectively open people up for relapse in this phase. You have to have discipline.
After a month of continued abstinence, you should start to get some serious relief for the cravings. The hope is at this point that you are also beginning to find things to enrich your life maybe that you forgotten when you were getting high. For me, it was the love and respect of my people and family that really gave me that natural injection of good vibes. Once I knew there was hope at normalcy, it became easier for me to get through those moments of intense cravings.
I hope this helps clear things up a little bit.
