Committing fully is scary because now you can’t blame half-effort if it doesn’t work.

Half effort keeps an explanation in reserve. If it does not work you can point at the part you held back, and your actual ability stays theoretically untested, which is comfortable. Full commitment takes that away, so the result means something, and that is what makes it frightening rather than the work itself.

Pick one thing to go all in on for a fixed stretch. Eight weeks with no excuse kept handy. You might find out you are not as good as you hoped. You will also find out what you can really do, which is worth more than the excuse was.