There is no manual. We learn, we grow, we change, we detach, we save, we let go, we connect. I too will never lose hope for my son. He's on his way to his third treatment because I stepped in again as I do when his addiction gets bad. Many A' s here tell us it took several attempts at rehab. Most say the conseq. of using have to be severe to choose sobriety. THROUGH the 5 yrs. there have been times I have had to detach and let go for long stretches of time to protect myself.
I don't let my son take advantage or bring chaos to my door. But his mental health issues and addiction are powerful. I work a program through alanon, and the support is awesome. It can NOT be all about them. We can not worry ourselves to bits.
It sounds like you are doing a fine job with the delicate balance and have good boundaries. Keep sharing. Lots of moms check in to help one another.