The fact that you don't know how to do something has no bearing on whether or not it is doable. People can and do develop real self-confidence, agency, and life satisfaction all of the time. The fact that you couldn't overcome a lifetime of disempowering narratives and experiences with a few months of therapy doesn't really say much about the possibilities of cognitive reframing techniques, or other types of interventions to gain those skills.

That being said, I'm glad that having a partner is working out well for you and I wish you all the best.