Unfulfilled PURPOSE needs new model. Help, please.

I am thankful, decisive, productive, positive and loving. My PURPOSE is to encourage others to live their best life.
Professionally I am able to live out my purpose. My struggle is with my family. I do love them as they are and desire to encourage them on their own journey. However, when they are sad, discouraged or struggling, I notice an unhealthy change in myself.

C Son struggling with career (medical issues. in pain. needs new career direction)
T I am a bad mom because he’s lacking progress and I can’t help him.
F Depressed & also Guilty for my own happiness
A Stop taking care of myself. (exercising, eating right, etc)
R Unhappy and disappointed with myself

Intellectually, I know this is untrue and I’m not responsible for their life choices.
How do I change my thinking? What is a better model?