Why does designing a system from scratch overwhelm me?

Facing a blank page and having to invent the whole thing is genuinely daunting, and the fear that your design will not hold up only makes the blankness heavier. This is not a sign you lack the ability. It is what happens when you try to hold the entire system in your head at once. No one can do that. The overwhelm comes from scale, so shrink it. You do not design the whole thing in one leap. You start with the simplest version that could possibly work, get it clear, and then add only what the next real need demands. Systems that hold up are usually grown, not conjured whole. Next time you start, write down just the core job the system must do, in one plain sentence. Design only for that first. Once it stands, ask what it actually needs next, and add that. Building in small, solid steps is not a lesser method. It is how the sound systems get made.