How do you do when, during the development of your application, you can't decide yourself what to do next.

You have no problem technically speaking, you have no problem to write clean code BUT you have a problem to decide yourself on what to code now.

And you spend time thinking and thinking again on your design, in the car, in the shower, and you cannot write a single line of code... I think we call this "analysis paralysis".

I hate being in this state ! How can you avoid this ? How do you do to not fall in this state ?

I think this occurs when we are writting a big chunk of code with no visible improvement, but I'm not sure...

UPDATE

Like some of you said, this problem is also what we call the "programmer's block" (analogy with the writer's block). Doing some TDD doesn't help because I'm stuck, I can't decide myself what class to code, what methods to put inside (even a name of method). Though I admit that it helps to break a big chunk of code into smaller ones. Like Talesh said my head becomes full of "what-if".