Personally, I found myself a lot more fulfilled in my hobbies when I learned to stop holding myself to the standards of people who don’t work the way that I do. In my case, that meant embracing the fact that I’ll always be a generalist, because I’m in it for the love of learning, and thus chasing novelty is a part of the fun. I need to be mindful that I do try to actually finish some projects, but I found that much easier to do once I stopped holding myself to competency standards that don’t map well onto why I engage with my hobbies.

It sounds like my experience is going to be quite different to your own, but I wonder whether part of your problem might be a similar thing of trying to chase after a model of hobby fulfillment that’s incompatible with why you do this stuff. I’d wager that fulfillment and accomplishment may still be possible for you, but they may come from a different source than your partner’s