How long does it take for a rootcanal to heal?

I had a rootcanal five days ago..the pain is still very strong..Have been living on IB Proven and they dont work for very long.....It was a moler tooth with three roots...Is this why it is still very painful?? Cannot sleep at night..what else can I take?? Dentist said tylenol but they dont even help...anyone have any suggestions?? thankyou