How do pain killers affect you having pfs

I never took an opiod before having pfs. Now that i have pfs and in my quest to stay sane ive taken a lot of opiods eppecially morphine and i can barely feel them. Ive seen old school junkies nod beyond belief injesting a fraction of what i would take and i still hardly feel them. I started the opiods after having pfs and i have never noded or become anebriated. I take them like an anti depressant. It makes me feel a little better and i dont trust pharma anything anymore basically. Im wondering if my brain has been changed and if other pfs sufferers have had the problem of barely getting any relief from opiods since having pfs. In general i feel recreational drugs( alcohol, weed, coke) far less than other people but opiods are my main interest.