There is a difference between dependence/addiction to painkillers. Dependence happens when you are prescribed painkillers for legitimate pain and then experience withdrawal symptoms when you stop taking the drug. Addiction, on the other hand, involves taking the medication in larger than prescribed dosages by getting multiple prescriptions from different doctors, buying the drug illegally or borrowing/stealing it from others.
If you just became dependent on the drug while following your doctor's instructions, there is no moral lapse involved. Look up the difference between addiction and dependence and take your info to the elders. I think you should appeal, if you want to stay in the org.
Your elders sound like they have a grudge against you. It's a real shame when you entrust private info to so-called spiritual men and they use it to hurt you rather than help you through the struggle.
Think about whether you want to be involved with people like them.