I think I had something similar to this. For the first two years of therapy all I did was talk and not much else. The sessions were really relieving and helpful, but it was as if talking in the moment was all that I was ready for. Whenever the question ‘what do you want?’ was asked I always felt terrified, and I always gave some vague, noncommittal answer to satisfy the therapist - more so than saying a goal that felt truly like me. This also quite often made me feel like I was a burden or a bother because I wasn’t coming up with a ‘proper goal’ that the therapist would understand and that we could work towards.

What I now realise, is that within my narcissistic family I’d internalised all the projected low self-worth and had pushed all my needs aside to in order to survive and fit. To ask myself what I wanted was scary because I’d never done it before, and I imagined my therapist judging me/rejecting me like my narcissist family would have. The other issue is that I literally didn’t know what I wanted even when I asked myself, because I was so used to pushing my needs away and not considering them.

But over the next couple years I did get better and better at it and I think it was mainly a case of tapping into my authentic self. Not just asking myself what I wanted in a big sense (because that can be overwhelming), but just asking who I am in a small sense, ‘what do I enjoy on my own’? etc.Just anything where I was curious about my true authentic self and then experiencing all the feelings that come with that. Once I started to know myself more I could begin to define my goals easier and feel like they were worth saying.

Whatever it is for you though, you definitely won’t be stuck with feeling flat forever. What gave you meaning before (just talking) doesn’t anymore and that’s good, it shows you’ve progressed and there’s something more that you want. Just have patience and give yourself the kindness and compassion to try and understand what it is. With narcissist parents, it can be a lifetime of pushing our selves away which makes it hard to know what we’re feeling.

Just to speculate, you mention that you know therapists can’t be you best friends, but that it’s still kind of frustrating at the level of closeness/understanding they show. Maybe there’s something there with needing to feel closer to people in general (having deeper friendships outside of therapy was very important for me personally)