Hi, I ve been taking codeine-( 300mg acetaminophen,15 mg caffeine and 8 mg codeine phosphate caplets) for about 2 months now and I take two every 4 hours. About 8 pills a day to treat severe back pain. I ve recently gone off it cold turkey and replaced with extra strength acetaminophen. I am experiencing some withdrawal symptoms, diarrhea, cramps, headaches, anxiety and an overall unwell feeling. How long can I expect this to last?