I think you should be proud of your achievement Kin
75 days is awesome - but although it may seem like a lifetime but in another way, it's not that long at all for life changes to occur. Progression will come
As far as your friend goes...I was a self appointed sobriety cop for a while. It got wearying and it ticked my friends off no end.
As long as your friend was in no danger, there was nothing for you to do, IMO.
Adults have the freedom to make bad decisions, and they need to take responsibility for those decisions...it's not your bag to carry