long answer : Read "Four Thousand Weeks".
Short answer: You have to chose a few and eschew the others. Tomorrow isn't guaranteed. There doesn't exist a reality in which you can "test your limits" in all of the areas. Because by its very definition - testing your limits means giving your -all-.
>so I really need to do better and find a way to focus. I just don't know how to do so
Makes it seem like you've bought into a fantasy that there exists a way to focus and do all of these things. It is tempting to think that, especially with all the so-called gurus and their productivity methods. Each technological feat and progress makes it seem like this timeless future is right around the corner. But the reality is that you will die. It could be tomorrow, it could be twenty years from now. But your time here is finite. So you must choose.
If you don't choose, you'll fall prey to the curse of middling interests. You'll hang around all of these interests and never really commit to any.
One practice that helped me with all my interests is to list them all in a spreadsheet and weigh the time investments I'm willing to make (they have to equal 1, and two hobbies can't have the same value).
When you think with that kind of urgency, it's easier to pick one thing to do. And really commit to it. E.g I sold/donated/gave away the tools for my other hobbies. Nothing says I can't get those back if (in the future) I decide not to continue with my current choices.