red, I took the liberty of starting a new thread for us. Please stay in touch.
I know it might feel like we are again coming down like a ton of bricks on something you thought was not only normal but 'lovely'. It must be easy for you to feel like we just don't understand, like our expectations of you are unreasonable. Maybe they are. But we have to have them, because your perceptions of 'normal' have been warped beyond recognition to a family not steeped in substance abuse. The first time I took my child to a party like the one you described would be the last, and I would have walked out by the time a second person sparked a joint.
If your daughter was able, physically, mentally, and emotionally, she would be screaming at you: 'Fuck him! What about ME? What about my precious life? You're the only one who can help me, and you aren't!' It's down to you. It must feel very hard to step up. But you can. You can dig deep.
What is the thing you'd need to see which would stop you putting into action your plan to leave at Christmas? Because I think anything less than 'H is in treatment and admits he needs to stop altogether' is gong to be too little.