In college, there was a class called programming practicum that basically taught this ramp. Early on you were given a UI for a basic shopping application, and had to code the backend, the last month was Tetris from scratch. I think around 50% of new students (not retaking the class) failed, because ramping from small to large is incredibly difficult.

I'd suggest one or more of the following:

• Download an open source project, and add something. It doesn't have to be useful or good, but you'll have to look at the structure, which will give you a feel of how large project is built.

• Just design your end project on paper, with arrows for dependencies. If you're making snake, you might have Snake head, snake tail, food, empty space, wall, board, current direction, etc. Might help you realize if your project is a lot bigger than you think.

• Take a basic project, and make it bigger and bigger. You'll probably do a lot of refactoring, and hopefully you'll learn how to make smaller projects that can easily be added to.

• If you know somebody experienced, tell them your idea for a project, and have them write your classes + some important methods, probably would take an hour or so. That way you can just fill the methods out, and always know what you need to do next.

Finally, whatever you do, you should probably use a basic MVC (Model, View, Controller) design pattern. Without going into much detail, put your view (UI) into 1+ classes, your controller (Input, output, etc) into 1+ classes, and your Model (Logic, Data, basically everything else) into several classes. It is an easy way to get basic organization.

Remember, this step is hard. It's true that some people simply cannot program, but you're probably just stuck at this stage. Good luck!