I don't think it's supposed to be fun. Like
methadone, it binds to opiate receptors to relieve withdrawal symptoms from opiates but very effectively. It's not a drug you would take to feel "high" and from what I've heard the binding to those receptors is very strong and takes time before they free up the sites so your natural endorphins take over. Like methadone this can take weeks or months depending on how long and how much you've taken. Check with your doctor, maybe they can prescribe some short-acting opiates to help you get thru the withdrawal. Good luck and hope you feel better soon.