Maisy, I understand how you feel. My daughter has emotional issues too, as do many of my family members......I know the struggles faced when our loved ones are mentally ill.
The biggest shift for me took place when I began to focus on my own health and well being. I'm glad you have a therapist to support you. And, Beattie's book was a big help to me too. You're doing a lot to take care of yourself and I believe that is what it takes for us to find our own joy in life.
Acupuncture helped me considerably with anxiety, it soothed my body/mind/spirit and brought me back to a peaceful feeling. I believe it was one of the most important components of my particular "tool box." I began changing a lot in my life so that I could not only cope and stop struggling, but I wanted to thrive and find peace of mind too. To that end I changed my diet and stopped sugar, dairy and caffeine. I also began walking/hiking regularly. It sounds so simple and yet each thing I did for myself helped so much as I navigated this terrain.
I also enjoyed reading books by Pema Chodron, who is a Buddhist nun who teaches about how to live in chaos and uncertainty. Elkhart Tolle's books also helped me to learn how to stay in the present moment, not scare myself with "future tripping" or rummage thru the past.....and to learn to accept what I can't change........to accept what is.
Each of us finds our own "tool box" of helpful things to do when we are in the throes of our adult troubled kids dramas and behaviors. You've done a good job of putting yours together.
I'm glad your son is still in the show.
We're all in this together.......