Client quit

I’m a health coach. I have a client that I’ve been working with for 4 months now. She was doing wonderfully well in the beginning. Her diabetes was under control. She was motivated and eating healthy. But in the last 6 weeks, she has fallen off the wagon. And today she quit coaching. I keep asking myself what I could have done to help her more. And I’m now questioning the effectiveness of my entire program.

C- Client quit
T- I didn’t do enough to help her
F- inadequacy, sadness
A- search for answers for how I could have helped her stay on track
R- ? Continued sadness and inadequacy?

I’m not sure what my question is. I guess I’m just looking for any advice you have to give.