I've since not been listened to at all,
Yeah, that sucks.
I have read some years ago tips for women on reddit how to deal with misygonic docs that don't take problems seriously. The gist of it was to present a story with your appearence that will help the doc emphatize with you (as I remember that was to present themselfs as business woman where illness prevents them from working.)
I guess something similar could be used for drug user that somehow is intepreted as addict.
I am uninformed but I heard from psychiatrist that weed has some negative effects on mental illness.
I would consider stopping weed for a bit, ride on painkillers(? I am totally clueless) for that time and try to get prescription for weed if it's possible (wikipedia says that it's legal for medical use.)