Yes, it’s been very frustrating because there’s things (songs, techniques) that are beyond my reach at the moment due to large gaps.

I get that. It’s satisfying to overcome those hurdles and frustrating to be blocked. Speaking for myself though, if I find I’m getting really frustrated by something that I’m supposedly doing for fun, it’s a sign that I might not be approaching it in the best way psychologically. I’m usually much happier when I try to have more of a zen ‘putting in the reps’ mindset. Then the periods of progress are like icing on the cake, not something I need to enjoy the thing.