Because codeine makes your BODY feel better, doesn't mess with mind like Hydrocodone, Oxycodone
all the scary stuff you read about on these forums.
Anyway, before everybody jumps on me that I don't know what I'm talking about, please consider ALL the meds you are on, ALL the shots you have been having, ALL the treatments you have been having, and what's the result? You are on the couch, trying not to cry.
So, logically, a different avenue might be considered.