A lot of people get a lot out of 12 step programs like NA or AA. part of that is the forth step, making amends. This is a process of making a list of the people who you have harmed, and, where possible, and safe, doing what you can to make amends. That might be apologising, that might be returning money that you stole if you did. It might be helping others to make up for the harm you did.

You can't undo the harm you did. But you can make amends. And grieve the shame.

Also I believe that it is important to look at the source of that shame before you were using. A study of iv drug users in Holland many years ago found that 80 percent had been abused as children. So there is a reasonable probability that something happened to you that you were using drugs to mask the shame.

That doesn't excuse any harm that you caused, but that betrayal of trust, if it happened, can also be grieved, in a healthy and supportive way, and healed.

Good luck with your journey. It isn't easy. But I promise that if you keep working, it will get better.