I'm afraid my self-improvement track and my future professional life will be the victim of this. I Would love to hear some suggestions or experiences regarding this issue.
In my early twenties I did similar things, thinking the world was wide and time was infinite until I realized I never finished any project at all or advanced beyond an absolute beginner stage. There is nothing wrong with trying out numerous things if you want to live an interesting life but if you can't ever commit to anything in the long-term maybe there's a reason for that.
I recommend the book: "Refuse to Choose!" by Barbara Sher.
Short intro: https://www.getmotivation.com/motivationblog/2017/04/barbara...
In short: get over the feeling of guilt first, then organize your multitudes of interests.
I mean, guitar for instance. Regular practice is good, but if you aren't having fun while doing it, it just means you feel like you are working during your free time. If you program for a living, doing it in your free time might feel like work even if you enjoy it. And so on.
I'll also mention that when trying out new things, it doesn't matter if you finish a project. You tried something, might or might not have liked it, and possibly figured it wasn't for you or that you rather like spending free time doing other things.
However, everything that I've explored has expanded my knowledge a bit. As an example, I used to draw years ago and although I don't anymore, if I'm asked to doodle something quickly (to show a diagram or if I'm playing Pictionary), I'm pretty adept at it. I wouldn't be this way if it weren't for sketching when I was younger.
The downside? It took decades to get reasonably competent in it all.
On hindsight, if I had to do it all over again, I'd probably take the Derek Sivers route[1] of spending a year (or 6 months, or 3 months) on a particular subject before moving onto the next thing.