I feel for you being in the middle of this difficult situation. It must be very hard to know what to do or say for the best but I’m sure you’re doing nothing wrong!
I work for a charity called The Icarus Trust which supports the families and friends dealing with the impact of addiction. We have experienced trained volunteers called ‘Family Friends’ who, if you got in touch you could talk with. They have all had experience of addiction in their own families so would understand where you are coming from. Maybe talking with one of them about how you are feeling and sharing experiences might help you to find a way forward.
You can contact us on help@icarustrust.org or visit the website http://www.icarustrust.org
I hope that this will help you. Good luck.