Modularization is a good thing, not a bad thing. With a large project its better to think of it as a set of components rather than one whole. At my current job we are stuck with a large monolithic legacy application and everyone is in agreement to break it into modules, which we are currently working on. Try to pick out the core "units" of a project that can be relatively self contained and work on those first. You should learn not to worry about starting with the UI, the UI shouldn't necessarily drive a software development project.