Is Al-Anon an option for you? What about Ala-Teen for at least the 14 year old?
Setting boundaries remains tricky for me, and I learned a lot from here and Al-anon about it. They can be pretty simple, but not easy to do.
The biggest thing I have learned in my experience is that when talking to a loved one it has to be about you....those Three C's have it nailed.
You did not cause it
You cannot control it and
You cannot cure it.
If I am trying to control a loved one with my expectations it does not work. I can only change me.