/lit/ - Literature

I finally realize I'm clueless on writing anything longer than a short story
Not because of length, more that my protag's goals are too straightforward or too abstract? Say
>protag goal is happiness, he does this by obtaining X. He gets X after undergoing trials 1-3, either story is over (A) or X doesn't fulfill him and therefore now he needs Y (B).

That's fine it itself, but I keep railroading the story into a short and if you ask me "what would the character do next?" I couldn't tell you a clue because they were more or less created only for that goal they obtained.

Sure, I can always add more stuff to make that process longer, but in my head adding more roadblocks and trials just drags (A) out and shifting goals in (B) comes off as if the character didn't truly understand their goals in the first place.