Can you try telling them that in the past when you abused drugs and alcohol it was a way of coping with your symptoms which you clearly wasn't getting the right support for ?

I too misused alcohol and drugs because I was desperate to feel better and these highly qualified people supposedly helping me failed me .
I'm currently not taking drugs or alcahol. If they offered me support for it I might take it only because I've been getting cravings for them lately quite often . however , if they just focused on that and the underlying various issues I need help with I would complain.
Its so wrong that they are trying to relate all of your problems to drink or drugs . many people have a few beers or a joint once in a while weather they have mental health problems or not . they need to focus on what you need and the must listen. If they don't I would consider complaining and maybe getting a new worker .

Hugs : Sophie