What makes therapy successful for people with C-PTSD? Looking for real-life experiences to challenge loved one's skepticism.

I’ve been in a relationship with a woman who has C-PTSD for some time. She believes therapy is useless—not just for PTSD, but for any mental health issue—and I want to challenge that notion. More importantly, I want to show her that there are real paths to healing beyond alcohol, which she can no longer drink due to medical reasons.

However, every time I try to discuss it, she dismisses my perspective because, in her eyes, I lack credibility as I don’t have personal experience with mental health struggles. But the good thing is that she's very fact-oriented, and I thought that hearing real-life success stories from others with C-PTSD might make her reconsider and eventually change her mind. She has a tendency to be more open-minded when presented with concrete facts and experience.

I’m particularly curious: • What made your therapy journey successful? • If therapy didn’t help at first, what eventually made a difference? • She once spent a year at an NHS institute with no progress. Could the environment have played a role? Could the fact that this happened during the first two years after the traumatic event made therapy unsuccessful? • To what extent does having a supportive person improve therapy outcomes? (At the time she stayed at the NHS institute, she had no family, friends, or even me in her life (which is the only thing that has changed).) • Could you mention the stages at time intervals, like how much time it took you to achieve each milestone?

I really appreciate all inputs from those who’ve been through this or who have a close one who has been through this,. Thanks in advance for everybody.