Don't fret, building stuff from scratch is hard: you have a thousand different decisions to make about the code and even just 1 wrong decision can make a codebase a clusterfuck.

But being good at debugging is a good base to learn how to build systems from. You'll see what naming conventions work well or invite confusion, what folder structure and project organization is less confusing, what design patterns lead to the trickiest bugs, etc.

Just keep at it.