It is a difficult position, because you would like to have some control over your life and the love you have. First let me be clear that my situation, like everyone's is unique and holds no direct correlation to your specific dilemma. I only wish to convey potential perspective and insight.
I was in the same position as you with my ex and unfortunately my efforts were not welcome, as she was attempting to get control of her own life without anyone's help, mine or a psychologist. I wanted to help, reach out, talk or anything to remain connected with her. It complicated things further that we had a young daughter and that added stress to us both.
In my opinion sufferers realize there is what they want and what they can do. They want to get better, but there is something inside them that they must deal with. Sometimes that is more painful than the external hurt they leave and inflict on loved ones. I know my ex did not want to leave her daughter and me, but she had to leave because the inside hurt was worse than the consequences of her choice to leave. In my case and in my opinion, she created an excuse to justify her actions, so her positive self image could remain intact. It is hard for anyone to see themselves as the bad guy, so we justify our actions to survive.
What I am getting at is, in my experience, I believe all those who suffer some persistent type of anxiety will do what ever it takes to mentally survive. Hopefully they do it in a positive way, like getting professional assistance and not running away from the pain. But, if they want to take flight from everything we can not stop them. No matter how much we love them we can not help them unless they accept it for themselves.
It all boils down to ensuring that they know that you are there to support them and care for them, not control them. My ex has called me when she needs help, because she knows I will be there for her. But, I still trigger her all the time when we have co-parenting conflicts. Just love them and hold on for as long as you can. Just don't forget to live yourself too. Try to save them for as long as you can, but do not let all of the circumstances claim you as a victim too.
Good luck, you are not alone and we are all sending best wishes your way.