You are taking codeine, a narcotic used for pain, and narcotics are addicting. Since you are not taking a huge dosage, if you cut down very slowly you should be able to get off the stuff. If you have trouble with this, see your doctor.
Only you can answer that question and if you are here asking i think you know the answer. There are a few red flags in your thread. Taking them that many days a week to relax and take the edge off is a big one. Do you want to quit taking these?